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Preservation Approaches for High-Traffic-Volume Roadways (2011)

Chapter: Appendix C - Summary of Preservation Questionnaire Responses

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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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Suggested Citation:"Appendix C - Summary of Preservation Questionnaire Responses." National Academies of Sciences, Engineering, and Medicine. 2011. Preservation Approaches for High-Traffic-Volume Roadways. Washington, DC: The National Academies Press. doi: 10.17226/14508.
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126 SHRP 2 Project R26 Questionnaire Start Date: 8/20/2008 End Date: 12/31/2008 Total Respondents Completed: 57 Partial Completions: 1 1.0 Pavement Preservation Experience/Background As shown below, respondents had a wide range of experience in pavement preservation. Not all respondents noted their years of experience. Range in Years of Experience Number of Respondents <5 7 6 to 10 7 11 to 15 3 16 to 20 4 >20 7 2.0 Questions Question 1 Please provide details of the typical average daily traffic (ADT) values associated with the traffic classifications of low, medium, and high traffic volume for rural and urban roadways in your agency. These classifications will be used as the basis for further questions in the questionnaire. Table C.1 presents the 58 agency responses regarding high-traffic-volume classification for rural and urban roadways. A P P E N D I X C Summary of Preservation Questionnaire Responses Rural, Low Volume is less than or equal to Rural, Medium Volume range is (e.g., . . . to . . .) Rural, High Volume is greater than or equal to Urban, Low Volume is less than or equal to Urban, Medium Volume range is (e.g., . . . to . . .) Urban, High Volume is greater than or equal to

127 Table C.1. Categorical Summary of Agency Designations for High-Volume Rural and Urban Roadways High-Traffic-Volume Categorizations Low ADT (<10,000 vpd) Medium ADT (10,000 to 19,999 vpd) High ADT (>--20,000 vpd) Louisiana DOT (7,000) Alaska DOT (10,000) Connecticut DOT (30,000) Michigan DOT (3,400 est.) Hawaii DOT (10,000) Rhode Island DOT (30,000) Missouri DOT (1,000) Maine DOT (10,000) South Carolina DOT (20,000) Montana DOT (6,000) Minnesota DOT (10,000) British Columbia (100,000) New York DOT (4,000/lane) New Hampshire (10,000) Pennsylvania DOT (2,000) Oklahoma DOT (10,000) South Dakota DOT (1,500) Ontario (10,000) Washington DOT (5,000) Alberta (5,000) FHWA-CFLHD (4,000) For agencies that make a distinction between rural and urban traffic volume categorizations: Georgia DOT (5,000 rural/8,000 urban) Wyoming DOT (10,000 rural/15,000 urban) Virginia DOT (20,000 rural/40,000 urban) Iowa DOT (3,500 rural) Iowa DOT (11,500 urban) Florida DOT (10,000 rural) Florida DOT (40,000 urban) Kansas DOT (3,000 rural) Kansas DOT (20,000 urban) Kentucky DOT (5,000 rural) Kentucky DOT (10,000 urban) Mississippi DOT, Newton (3,000–7,000 rural) Mississippi DOT, Newton (20,000 urban) Mississippi DOT, Batesville (2,000 rural) Mississippi DOT, Batesville (10,000 urban) Mississippi DOT, Tupelo (3,000–7,000 rural) Mississippi DOT, Tupelo (20,000 urban) Nevada DOT (10,000 rural) Nevada DOT (100,000 urban) New Mexico DOT (5,000 rural) New Mexico DOT (15,000 urban) North Carolina DOT (5,000 rural) North Carolina DOT (10,000 urban) Tennessee DOT (5,000 rural) Tennessee DOT (10,000 urban) Texas DOT (1,000 rural) Texas DOT (10,000 urban) Manitoba (4,000 rural) Manitoba (10,000 urban) Quebec (8,000 rural) Quebec (20,000 urban) Organizations: NAPA (10,000); NACE (15,000 rural/60,000 urban). Other: Colorado DOT categorizes by ESALs. Caltrans categorizes by traffic index, TI: TI ≤ 18 rural and TI ≤ 15 urban, where TI = 9.0 × (ESAL ÷ 106)0.119. Utah DOT (Region 4) categorizes by Interstate or non-Interstate (25,000 ADT and 2,500 ADT, respectively). City of Phoenix, Ariz., categorizes by 20,000 ADT rural, 50,000 ADT urban. Question 2 There are a variety of factors that influence the selection of a preventive maintenance treatment. Please rank the following 18 factors in terms of the level of importance that your agency places on each factor when selecting the most appropriate preventive maintenance treatment. Table C.2 presents the 58 agency responses and includes summary statistics associated with the answers.

128 Question 3 Using the traffic classifications you defined in question 1, which of the following treatments does your agency apply in a preven- tive manner (i.e., to pavements in good condition) on RURAL roadways? Check all boxes that apply or mark “not used” if this treatment is not used by your agency. Tables C.3 and C.4 present the 58 agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included. Table C.2. Summary of Factors Influencing Agency Selection of Preventive Maintenance Treatment Not Important Low Priority Medium Priority High Priority Number of Factor % Response % Response % Response % Response Respondents Agency experience with treatment 2 5 40 53 58 Material availability 2 7 48 43 58 Previous treatment failure 0 7 41 52 58 Alternate route availability 26 40 28 7 58 Safety concerns 0 3 21 76 58 Perception 2 36 50 12 58 Noise 19 39 40 2 57 Work zone 2 22 59 17 58 Treatment cost 0 0 26 74 58 Traffic volume 0 7 40 53 57 Experienced contractor availability 5 14 60 21 58 Bias against treatment 12 32 45 11 56 Traffic control requirements 2 24 55 19 58 Closure time 2 17 57 24 58 Liability concerns 4 21 42 33 57 Durability/expected treatment life 0 2 35 63 57 Production rates 9 29 52 10 58 Time before trafficking 3 21 55 21 58 Risk associated with treatment failure 2 5 57 36 58 Climate 7 28 44 21 57

Table C.3. Summary of Preventive Maintenance Treatments Used on HMA RURAL Roadways Distinguished by Traffic Volume Classifications Defined in Question 1 Treatments for Hot-Mix Asphalt (HMA)– Low Traffic Medium Traffic High Traffic Not Used Number of Surfaced Pavements % Response % Response % Response % Response Respondents Crack fill 74 74 74 19 58 Crack seal 83 88 86 9 58 Cape seal 9 14 9 79 58 Fog seal 45 26 14 48 58 Scrub seal 14 16 2 83 58 Slurry seal 35 25 11 54 57 Rejuvenators 16 18 11 77 57 Single-course microsurfacing 42 60 54 26 57 Multiple-course microsurfacing 31 51 44 42 55 Single-course chip seal 88 62 24 12 58 Multiple-course chip seal 55 43 11 39 56 Chip seals with polymer-modified asphalt binder 64 57 31 22 58 Ultra-thin bonded wearing course (e.g., NovaChip) 16 33 48 48 58 Thin HMA overlay (<40 mm [<1.5 in.]) 64 71 66 16 58 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 55 67 64 22 58 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 24 22 22 66 58 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 22 21 19 67 58 Cold-in-place recycling (<100 mm [<4.0 in.]) 41 38 29 45 58 Profile milling (diamond grinding) 17 28 41 57 58 Ultra-thin whitetopping 10 17 16 72 58 Drainage preservation 50 50 59 43 56 Other (see below) 46 38 31 54 13 129 Other Treatments (Table C.3): • Our minimum HMA depth is 1.5 in., which we would use on any traffic volume. We have experimented with 4.75 mm “sand” mixes less than this, but not typically used. • Rubber chip seals. • 1.5 in. HMA mill and fill. • Spot strip sealing. • HMA thin overlay <60 mm. Agency Comments (Table C.3): • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grind- ing seldom used. Have recently applied OGFC (3⁄4 in.) to a few projects. Whitetopping seldom used due to high cost. Not considered preventive maintenance but rather major rehab. • All state chip seal receive fog seal.

Other Treatments (Table C.4): • HMA from 40 to 60 mm. Agency Comments (Table C.4): • We only have 154 lane miles of PCC pavements [. . .], mostly in [. . .] metropolitan area[s]. • No concrete roads [. . .]. • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grinding seldom used. Have recently applied OGFC (3⁄4 in.) to a few projects. Whitetopping seldom used due to high cost. Not considered preventive maintenance but rather major rehab. Question 4 Using the traffic classifications you defined in question 1, which of the following treatments does your agency apply in a preven- tive manner (i.e., to pavements in good condition) on URBAN roadways? Check all boxes that apply or mark “not used” if this treatment is not used by your agency. Tables C.5 and C.6 present the 58 agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included. 130 Table C.4. Summary of Preventive Maintenance Treatments Used on PCC RURAL Roadways Distinguished by Traffic Volume Classifications Defined in Question 1 Treatments for Portland Cement Low Traffic Medium Traffic High Traffic Not Used Number of Concrete (PCC) Pavements % Response % Response % Response % Response Respondents Concrete joint resealing 39 55 73 25 56 Concrete crack sealing 42 56 71 24 55 Diamond grinding 27 48 77 25 56 Diamond grooving 5 12 34 66 56 Partial-depth concrete pavement patching 36 51 69 29 55 Full-depth concrete pavement patching 38 62 84 16 56 Dowel bar retrofit (load-transfer restoration) 14 32 59 39 56 Thin PCC overlays 5 9 16 80 55 Ultra-thin bonded wearing course 11 18 27 71 56 (e.g., HMA < 25 mm [1 in.]) Thin HMA overlay (<40 mm [<1.5 in.]) 15 31 31 58 55 Drainage preservation 28 39 54 44 54 Other: (see below) 0 0 8 92 12

131 Table C.5. Summary of Preventive Maintenance Treatments Used on HMA URBAN Roadways Distinguished by Traffic Volume Classifications Defined in Question 1 Treatments for Hot-Mix Asphalt (HMA)– Low Traffic Medium Traffic High Traffic Not Used Number of Surfaced Pavements % Response % Response % Response % Response Respondents Crack fill 71 71 75 18 56 Crack seal 84 88 88 7 56 Cape seal 9 11 5 84 57 Fog seal 28 19 11 65 57 Scrub seal 14 9 2 84 57 Slurry seal 25 25 16 58 57 Rejuvenators 14 16 12 80 56 Single-course microsurfacing 53 58 46 28 57 Multiple-course microsurfacing 36 47 42 44 55 Single-course chip seal 69 38 13 31 55 Multiple-course chip seal 43 30 4 57 54 Chip seals with polymer-modified asphalt binder 60 37 18 37 57 Ultra-thin bonded wearing course (e.g., NovaChip) 18 40 47 49 57 Thin HMA overlay (<40 mm [<1.5 in.]) 67 64 55 25 55 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 68 70 66 20 56 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 30 27 27 59 56 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 25 19 14 70 57 Cold-in-place recycling (<100 mm [<4.0 in.]) 30 26 16 63 57 Profile milling (diamond grinding) 15 26 39 61 54 Ultra-thin whitetopping 14 26 18 65 57 Drainage preservation 48 46 52 46 54 Other (see below) 33 11 11 67 9 Other Treatments (Table C.5): • Our minimum HMA depth is 1.5 in., which we would use on any traffic volume. We have experimented with 4.75 mm “sand” mixes less than this, but not typically used. • Rubber chip seals. • 1.5 in. HMA mill and fill. • Spot strip sealing. Agency Comments (Table C.5): • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grinding seldom used. Have recently applied OGFC (3⁄4 in.) to a few projects. Whitetopping seldom used due to high cost. Not considered preventive maintenance but rather major rehab.

132 Table C.6. Summary of Preventive Maintenance Treatments Used on PCC URBAN Roadways Distinguished by Traffic Volume Classifications Defined in Question 1 Treatments for Portland Cement Low Traffic Medium Traffic High Traffic Not Used Number of Concrete (PCC) Pavements % Response % Response % Response % Response Respondents Concrete joint resealing 45 64 78 20 55 Concrete crack sealing 47 62 73 22 55 Diamond grinding 29 51 75 25 55 Diamond grooving 8 12 31 69 52 Partial-depth concrete pavement patching 38 53 62 35 55 Full-depth concrete pavement patching 44 64 82 18 55 Dowel bar retrofit (load-transfer restoration) 18 31 55 42 55 Thin PCC overlays 4 9 11 85 55 Ultra-thin bonded wearing course 11 18 21 71 56 (e.g., HMA < 25 mm [1 in.]) Thin HMA overlay (<40 mm [<1.5 in.]) 17 28 26 63 54 Drainage preservation 31 38 48 50 52 Other (see below) 0 0 0 100 12 Agency Comments (Table C.6): • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grinding seldom used. Have recently applied OGFC (3⁄4 in.) to a few projects. Whitetopping seldom used due to high cost. Not considered preventive maintenance but rather major rehab. • Don’t have urban PCC pavements. Question 5 Do you use a different set of treatments on RURAL high-traffic-volume roads than on RURAL low-traffic-volume roads? If “Yes,” please check those treatments that you don’t consider applicable for RURAL high-traffic-volume roadways. Based on 56 total responses, the following percentages of “Yes” and “No” were observed: • Yes: 62% • No: 38% The 56 respondents who answered “Yes” to question 5 were asked to answer the multiple parts of question 5. These detailed results are provided below in Tables C.7 and C.8. Additional agency comments are also included.

133 Table C.7. Summary of Preventive Maintenance Treatments Considered Not Applicable for HMA RURAL Roadways Not Applicable Treatments for Hot-Mix Asphalt (HMA)–Surfaced Pavements % Checked Crack fill 6 Crack seal 6 Cape seal 70 Fog seal 51 Scrub seal 54 Slurry seal 51 Rejuvenators 34 Single-course microsurfacing 20 Multiple-course microsurfacing 20 Single-course chip seal 83 Multiple-course chip seal 80 Chip seals with polymer-modified asphalt binder 71 Ultra-thin bonded wearing course (e.g., NovaChip) 26 Thin HMA overlay (<40 mm [<1.5 in.]) 26 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 9 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 40 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 46 Cold-in-place recycling (<100 mm [<4.0 in.]) 49 Profile milling (diamond grinding) 37 Ultra-thin whitetopping 57 Drainage preservation 9 Other (see below) 3 Agency Comments (Table C.7): • Marked treatments we currently use and don’t consider applicable.

Agency Comments (Table C.8): • We do not use concrete on these roads. Question 6 Do you use a different set of treatments on URBAN high-traffic-volume roads than on URBAN low-traffic-volume roads? If “Yes,” please check those treatments that you don’t consider applicable for URBAN high-traffic-volume roadways. Based on 57 total responses, the following percentages of “Yes” and “No” were observed: • Yes: 54% • No: 46% The 57 respondents who answered “Yes” to question 6 were asked to answer the multiple parts of question 6. These detailed results are provided in Tables C.9 and C.10. 134 Table C.8. Summary of Preventive Maintenance Treatments Considered Not Applicable for PCC RURAL Roadways Not Applicable Treatments for Portland Cement Concrete (PCC) Pavements % Checked Concrete joint resealing 8 Concrete crack sealing 8 Diamond grinding 4 Diamond grooving 33 Partial-depth concrete pavement patching 17 Full-depth concrete pavement patching 8 Dowel bar retrofit (load-transfer restoration) 21 Thin PCC overlays 62 Ultra-thin bonded wearing course (e.g., HMA < 25 mm [1 in.]) 75 Thin HMA overlay (<40 mm [<1.5 in.]) 62 Drainage preservation 8 Other (see below) 4

135 Table C.9. Summary of Preventive Maintenance Treatments Considered Not Applicable for HMA URBAN Roadways Not Applicable Treatments for Hot-Mix Asphalt (HMA)–Surfaced Pavements % Checked Crack fill 9 Crack seal 6 Cape seal 50 Fog seal 69 Scrub seal 72 Slurry seal 62 Rejuvenators 50 Single-course microsurfacing 28 Multiple-course microsurfacing 22 Single-course chip seal 91 Multiple-course chip seal 88 Chip seals with polymer-modified asphalt binder 84 Ultra-thin bonded wearing course (e.g., NovaChip) 31 Thin HMA overlay (<40 mm [<1.5 in.]) 28 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 12 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 38 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 53 Cold-in-place recycling (<100 mm [<4.0 in.]) 59 Profile milling (diamond grinding) 28 Ultra-thin whitetopping 44 Drainage preservation 9 Other (no comments) 0 Table C.10. Summary of Preventive Maintenance Treatments Considered Not Applicable for PCC URBAN Roadways Not Applicable Treatments for Portland Cement Concrete (PCC) Pavements % Checked Concrete joint resealing 5 Concrete crack sealing 5 Diamond grinding 5 Diamond grooving 23 Partial-depth concrete pavement patching 14 Full-depth concrete pavement patching 5 Dowel bar retrofit (load-transfer restoration) 23 Thin PCC overlays 55 Ultra-thin bonded wearing course (e.g., HMA < 25 mm [1 in.]) 73 Thin HMA overlay (<40 mm [<1.5 in.]) 55 Drainage preservation 14 Other (no comments) 5

136 Agency Comments (Table C.11): • Rubberized surface treatment. • 1.5 in. HMA mill and fill. • Fog seal on all chip seals. Table C.11. Summary of Comparative Use of Preventive Maintenance Treatment for High-Traffic-Volume HMA Roads with High Truck Traffic Compared with Those with Low Truck Traffic Treatments for Hot-Mix Asphalt (HMA)– More Likely No Difference Less Likely Not Used Number of Surfaced Pavements % Response % Response % Response % Response Respondents Crack fill 2 80 0 18 56 Crack seal 2 91 0 7 56 Cape seal 0 16 5 79 57 Fog seal 0 28 11 61 57 Scrub seal 0 16 5 79 57 Slurry seal 0 19 21 60 57 Rejuvenators 0 19 5 75 57 Single-course microsurfacing 7 50 16 27 56 Multiple-course microsurfacing 14 45 5 36 56 Single-course chip seal 0 38 32 30 56 Multiple-course chip seal 4 27 23 46 56 Chip seals with polymer-modified asphalt binder 19 30 16 35 57 Ultra-thin bonded wearing course (e.g., NovaChip) 14 35 5 46 57 Thin HMA overlay (<40 mm [<1.5 in.]) 9 58 14 19 57 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 21 20 12 16 56 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 4 30 11 56 57 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 4 30 4 63 57 Cold-in-place recycling (<100 mm [<4.0 in.]) 4 33 18 46 57 Profile milling (diamond grinding) 9 38 0 53 55 Ultra-thin whitetopping 14 20 11 55 56 Drainage preservation 6 59 0 35 54 Other (see below) 0 31 8 62 13 Question 7 Please indicate whether you are more or less likely to use each treatment on high-traffic-volume roads that have HIGH TRUCK traffic volumes as compared to those with little truck traffic. If you do not use the treatment, then indicate that it is a treatment that is not used by your agency. Tables C.11 and C.12 present the 57 agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included.

137 Table C.12. Summary of Comparative Use of Preventive Maintenance Treatment for High-Traffic-Volume PCC Roads with High Truck Traffic Compared to Those with Low Truck Traffic Treatments for Portland Cement More Likely No Difference Less Likely Not Used Number of Concrete (PCC) Pavements % Response % Response % Response % Response Respondents Concrete joint resealing 7 75 0 18 55 Concrete crack sealing 5 73 2 20 55 Diamond grinding 13 65 0 22 55 Diamond grooving 6 39 2 54 54 Partial-depth concrete pavement patching 4 67 4 25 55 Full-depth concrete pavement patching 11 73 2 15 55 Dowel bar retrofit (load-transfer restoration) 24 40 2 35 55 Thin PCC overlays 0 22 9 69 55 Ultra-thin bonded wearing course 2 29 5 64 55 (e.g., HMA < 25 mm [1 in.]) Thin HMA overlay (<40 mm [<1.5 in.]) 4 31 15 51 55 Drainage preservation 4 61 0 35 54 Other (no comments) 0 17 0 83 12 Question 8 For those treatments that were checked as “Not Used” on RURAL high-traffic-volume roadways under question 3, please indi- cate the reason(s) it is not being used. Check all boxes that apply. Tables C.13 and C.14 present the 57 agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included.

138 139 Table C.13. Summary of Reasons Why Preventive Maintenance Treatment for RURAL High-Traffic-Volume HMA Roads Are Not Used Percent Responses emiT/ytilibaruDdedeeNdesaercnIsaiBfo kcaLfo kcaL itcudorPdetcepxEytilibaiLytefaSerusolCcfifarTfi ksiRsuoiverPtsniagAfo kcaLdecneirepxEycnegA rof stnemtaerT tnemevaP decafruS-AMH on before Treatment Number of ioNefiLsnrecnoCsnrecnoCemiTlortnoCsruccO eruliaFeruliaFtnemtaerTslairetaMsrotcartnoCecneirepxEsyawdaoR emuloV-cfifarT-hgiH LARUR se Rates Trafficking Cost Climate Responses 9022022114400011001102265llfi kcarC 307603303300033000000laes kcarC 93062300323383535138378laes epaC 2306900431374212121618202235laes goF 4405200327750706122328laes burcS 5306900049711166113206215laes yrrulS 930500082123285386238197srotanevujeR 41041000460770773471234gnicafrusorcim esruoc-elgniS 71042000920060669268156gnicafrusorcim esruoc-elpitluM 5204806144258202616304230421laes pihc esruoc-elgniS 82041401134341241419223520441laes pihc esruoc-elpitluM 420880833645271219252520852rednib tlahpsa defiidom-remylop htiw slaes pihC 120250005000550191018426)pihCavoN ,.g.e( esruoc gniraew dednob niht-artlU 4104100046000070127092)].ni 5.1<[ mm 04<( yalrevo AMH nihT 41041000170000410410092)].ni 5.1<[ mm 04<( yalrevo AMH dna gnillim dloC 23021000353003210216665)].ni 57.0<[ mm 02<( yalrevo AMH niht-artlU 7339100072003311914206494)].ni 59.1<[ mm 05<( gnilcycer AMH ecalp-ni toH 7205170022001141176200365)].ni 0.4<[ mm 001<( gnilcycer ecalp-ni-dloC 62432000320000042102196)gnidnirg dnomaid( gnillim elfiorP 433920004200510635106286gnippotetihw niht-artlU 410707070000001206339noitavreserp eganiarD 200050005050505050505050005)woleb ees( rehtO Agency Comments (Table C.13): • Rubberized chip seal. • Generally, the techniques are not available in Québec. • Basically, not enough volume of work to support all the different types of treatments. • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grind- ing seldom used. Have recently applied OGFC (3⁄4in.) to a few projects. Whitetopping seldom used due to high cost. Not considered preventive maintenance but rather major rehab.

140 141 Table C.14. Summary of Reasons Why Preventive Maintenance Treatment for RURAL High-Traffic-Volume PCC Roads Are Not Used Percent Responses emiT/ytilibaruDdedeeNdesaercnIsaiBfo kcaLfo kcaL bnoitcudorPdetcepxEytilibaiLytefaSerusolCcfifarTfi ksiRsuoiverPtsniagAfo kcaLdecneirepxEycnegA LARUR rof stnemtaerT tnemevaP CCP efore Treatment Number of etaResioNefiLsnrecnoCsnrecnoCemiTlortnoCsruccO eruliaFeruliaFtnemtaerTslairetaMsrotcartnoCecneirepxEsyawdaoR emuloV-cfifarT-hgiH s Trafficking Cost Climate Responses 307600000000033330033gnilaeser tnioj etercnoC 307600000000033330033gnilaes kcarc etercnoC 400500000000005205257gnidnirg dnomaiD 220320055000000908168gnivoorg dnomaiD 701704107500000929204134gnihctap tnemevap etercnoc htped-laitraP 500400002000000020006gnihctap tnemevap etercnoc htped-lluF 3108300080088851805196)noitarotser refsnart-daol( tfiorter rab lewoD 4302321005330813635108165syalrevo CCP nihT 72422000844000479105195 esruoc gniraew dednob niht-artlU (e.g., HMA < 25 mm [1 in.]) 22050004600004141320023)].ni 5.1<[ mm 04<( yalrevo AMH nihT 41012070410000071209217noitavreserp eganiarD 20000000000000005001)woleb ees( rehtO Agency Comments (Table C.14): • Generally, the techniques are not available in Québec. • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grinding seldom used. Have recently applied OGFC (3⁄4in.) to a few projects. Whitetopping seldom used due to high cost. Not con- sidered preventivemaintenance but rather major rehab. • We have only 1 PCC section (5.8 km long). • Maine DOT has very few PCC pavements. • No PCC pavements.

142 143 Table C.15. Summary of Reasons Why Preventive Maintenance Treatment for URBAN High-Traffic-Volume HMA Roads Are Not Used Percent Responses emiT/ytilibaruDdedeeNdesaercnI saiB fo kcaLfo kcaL oitcudorPdetcepxEytilibaiLytefaSerusolCcfifarTfi ksiRsuoiverPtsniagAfo kcaLdecneirepxEycnegArof stnemtaerT tnemevaP decafruS-AMH n before Treatment Number of ioNefiLsnrecnoCsnrecnoCemiTlortnoCsruccO eruliaFeruliaFtnemtaerTslairetaMsrotcartnoCecneirepxEsyawdaoR emuloV-cfifarT-hgiH NABRU se Rates Trafficking Cost Climate Responses 8000210830210210212105226llfi kcarC 2000000010000000000laes kcarC 53011600413366631101368laes epaC 23009001352136161992209165laes goF 9300300828853500101297laes burcS 330390063215121606901216laes yrrulS 530000062711196601137138srotanevujeR 210710008500807103307105gnicafrusorcim esruoc-elgniS 71021000530060664208156gnicafrusorcim esruoc-elpitluM 820470414575528141642363047laes pihc esruoc-elgniS 13001300124259131312391230631laes pihc esruoc-elpitluM 03001700173353271317332030732rednib tlahpsa defiidom-remylop htiw slaes pihC 91035000110000051202436)pihCavoN ,.g.e( esruoc gniraew dednob niht-artlU 6102100096060060916652)].ni 5.1<[ mm 04<( yalrevo AMH nihT 210330008508008080024)].ni 5.1<[ mm 04<( yalrevo AMH dna gnillim dloC 92041000843300707134195)].ni 57.0<[ mm 02<( yalrevo AMH niht-artlU 33381000420330698106384)].ni 59.1<[ mm 05<( gnilcycer AMH ecalp-ni toH 7202211000300117749109184)].ni 0.4<[ mm 001<( gnilcycer ecalp-ni-dloC 3202200071000000710907)gnidnirg dnomaid( gnillim elfiorP 13061013062003163163106286gnippotetihw niht-artlU 210000000000005203329noitavreserp eganiarD 200050005050505050505050005)woleb ees( rehtO Agency Comments (Table C.15): • Rubberized chip seal. • Generally the techniques are not available in Québec. • Not enough volume of work to use all the different treatments. Question 9 For those treatments that were checked as “Not Used” on URBAN high-traffic-volume roadways under question 4, please indi- cate the reason(s) it is not being used. Check all boxes that apply. Tables C.15 and C.16 present the 57 agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included. • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grinding seldom used. Have recently applied OGFC (3⁄4 in.) to a few projects. Whitetopping seldom used due to high cost. Not considered preventive maintenance but rather major rehab.

145144 • Fog seal shoulders. • Incorporate crack filling and sealing into systematic program. Reasons cited for the above treatments not currently being used were as follows (based on 11 respondents): • Not fully developed: 27% • No proven performance: 9% • Other reasons: 64% Agency Comments: • Cannot use those treatments with dedicated funding. • Not fully accepted yet (2 respondents). • No proven performance and inexperienced contractors. • Allocation of limited funding (2 respondents). • Lack of local capacity. Question 11 Please list the three MOST successful pavement preservation treatment types used on your RURAL high-traffic-volume road- ways, starting with the most successful, and briefly explain why each treatment is successful for your agency. Treatment 1 • Crack seal. MDT has aggressively sealed cracks for about 8–9 years. Keeping water out of the base and subgrade has improved performance. Of course timing is critical. MDT tries to make sure that all cracks are sealed prior to placing a chip seal. • Bituminous resurfacing. Relatively less risk, 8–12 years life. • Cold in-place recycling. Agency Comments (Table C.16): • Generally the techniques are not available in Québec. • Crack treatments not a systematic process. Some districts perform work via maintenance personnel. Diamond grinding seldom used. Have recently applied OGFC (3⁄4 in.) to a few projects. Whitetopping seldom used due to high cost. Not considered preventive maintenance but rather major rehab. • We have no urban PCC highways. • No PCC pavements. • Little experience with PCC pavements. Question 10 In addition to the treatments included in questions 3 or 4, are there other treatments that you are considering using, but have not? If “Yes,” please identify any treatments that you considered using but the treatment is not fully developed, does not yet have proven performance, or was not used because of another reason. Based on 56 total responses, the following percentages of “Yes” and “No” were observed: • Yes: 12% • No: 88% Other considered treatment types listed included: • Most of the other treatments that are checked as not used. • Hot in-place recycling. • Microsurfacing (2 respondents). • Chip seals for high-volume roads. • Cold in-place recycling (2 respondents). • 1 in. HMA overlay. Table C.16. Summary of Reasons Why Preventive Maintenance Treatment for URBAN High-Traffic-Volume PCC Roads Are Not Used Percent Responses emiT/ytilibaruDdedeeNdesaercnI saiB fo kcaLfo kcaL rTerofebnoitcudorPdetcepxEytilibaiLytefaSerusolCcfifarTfi ksiRsuoiverPtsniagAfo kcaLdecneirepxEycnegArof stnemtaerT tnemevaP CCP eatment Number of ioNefiLsnrecnoCsnrecnoCemiTlortnoCsruccO eruliaFeruliaFtnemtaerTslairetaMsrotcartnoCecneirepxEsyawdaoR emuloV-cfifarT-hgiH NABRU se Rates Trafficking Cost Climate Responses 303300000000033330033gnilaeser tnioj etercnoC 405200000000052520005gnilaes kcarc etercnoC 500400000000000200206gnidnirg dnomaiD 12092000100000004104118gnivoorg dnomaiD 903301104400000332201122gnihctap tnemevap etercnoc htped-laitraP 40520000000000520005gnihctap tnemevap etercnoc htped-lluF 51033700720031310231310706)noitarotser refsnart-daol( tfiorter rab lewoD 3303390033002135134202185syalrevo CCP nihT 7207000140000476205195 esruoc gniraew dednob niht-artlU (e.g., HMA < 25 mm [1 in.]) 4204000260400412710033)].ni 5.1<[ mm 04<( yalrevo AMH nihT 21071000710000083305276noitavreserp eganiarD 1000000000000000001)woleb ees( rehtO

• We have had success with the treatments we use. I wouldn’t want to rank them in order. The one course mill and resur- faces and concrete pavement repairs are “high end” fixes for CPM and work well with more distressed pavements. Surface sealing (crack seals, chip seals, micro, ultra-thin HMA) are successful at sealing the pavement and extending service life. • Thin overlays with fabric reinforcement. Restores ride, eliminates ruts, and extends life. • Mill and HMA overlay. • Crack sealing. Best value for the cost, first line of defense in pavement preservation, retards future deterioration. • Mill 2 in. and put back 2 in. of HMA, followed by open graded friction course. This is probably not really a preventive maintenance treatment. • Thin mill (profile up to 1.5 in.) and HMA overlay, 1.5 in. This is our standard treatment, high degree of familiarity, large contractor capability. • Thin hot-mix overlays. Lots of experience, a variety of mixes that can be used for different applications, dense graded, per- meable friction courses, SMA. • 1 in. rubber modified AC overlay has allowed the asphalt to remain flexible and strong given our extremely high tem- peratures. • Crack sealing. It keeps moisture out of the pavement structure. This moisture can cause stripping in HMA pavements as well as localized pavement failure due to wet subgrades. • Crack seal/fill. Studies prove this treatment extends the life of the pavement if treatment applied at the right time. • Milling with thin asphalt overlay. Removes surface distresses, improves ride, preserves geometrics. Lower life-cycle cost than other treatments. • Crack and/or joint sealing. Very cost-effective method to extend pavement life utilizing our own forces and some con- tractor’s when necessary. • Cold in-place recycling with an overlay. Note: we do not consider this a preservation treatment, but rather a cost- effective rehabilitation. These treatments have had outstanding performance for us. With a 3 to 4 in. recycling depth and a designed overlay thickness (typically 2 to 4 in.), we have achieved in access of 20 years of performance life. Addi- tionally, the reliability of this treatment has been very good. We have not experienced any significant premature failures with this treatment. • Cold plane and overlay. Large number of experienced contractors. • Chip sealing. MN/DOT has spent a large amount of time developing better methods, specifications, and training on chip sealing. • Rubberized asphalt chip seal—cracking. • Cold milling, HMA overlay <1.5 in. for rutting. • Chip seal with flush coat. Lower cost, reasonable service life. • Chip seal. Cost-effective. • Microsurfacing. Good bond with pavement. Fast application. • Mill and overlay with HMA 1.5 to 2 in. Successful due to good durability and experienced contractors. • Surface prep (milling or leveling) and a 2 in. overlay. Surface prep is often needed to allow a high level of smoothness. Higher-quality construction and better performance with 2 in. lift overlays than 1.5 in. overlays. • Thin hot-mix overlay (AK, polymer). • Crack filling/sealing. Detour water from base. • Rubberized slurry seal. Familiar with its limits, increased longevity compared to conventional slurry seal. • Seal coat: Long history of good performance, >35 years. Candidate selection criteria through PMS. Excellent QA process, 2 provincial crews (in house). • Crack sealing. Economic and good strategy. • Diamond grooving of PCC. Life of treatment exceeded expectations. • Thin HMA OL (2 in. or less). Capable of adding structure. • Chip seals with polymer-modified asphalt binder with lightweight aggregate. Seals cracks and keeps the water out at a relatively minimal expense and extends the life of the previous treatment. Also doesn’t raise the grade of the roadway much. • Thin HMA overlay. • Thin lift overlay. • Cold milling and HMA overlay 1.5 in. • Crack sealing. Good cost-to-benefit ratio. 146

• Crack filling. Cost-efficient, easy to realize, performance. • Crack and joint sealing. First step in pavement preservation. Keep the water out. • Fog seal. Inexpensive, retards oxidation. • Chip seals. Coat, protect, and rejuvenate existing pavement, retard the rate of oxidation and asphalt hardening with age, seal narrow cracks in the pavement from infiltration of water, stops raveling and restores pavement friction. • Crack fill/seal. Keeps moisture out. • Chip seal with polymer. Good experience and durability. • Cold milling/overlay. Ability to reuse milled pavement in recycled mix. Able to remove surface distress while strengthen- ing road. • Cold milling and overlay at least 2 in. Restores pavement section and eliminates variation of compaction due to rutting. • Seal coat. Provides needed water seal and good friction course. • Cold mill and thin overlay. Restores pavement to near new condition. Cheaper than full rehab on roads with adequate structural capacity or strength. • 1.8 in. HMA overlay on HMA. Where appropriate, adds life to highways at relatively low cost. • Chip seal. Seals deficiency in pavement such as segregation and provides wet weather and winter skid enhancement. • Crack seal/fills. This is our most prevalent preservation technique, but success is anecdotal. We do not monitor for crack- ing in pavement management. • 1 to 1.5 in. HMA. Both our contractors and agency personnel have a lot of experience with this treatment. • Crack sealing. Significant experience within CDOT maintenance forces. • Thin HMA overlay. Provides for longest expected life. • 1.5 in. HMA overlay with shim. Experienced contractors and agency personnel. It’s a known material. Treatment 2 • Chip seal. MDT places chip seals on pavements that are 5–7 years old (time since last overlay or rehabilitation). This has been a very effective treatment. • Crack sealing. Inexpensive, prolongs life of surface. • Chip seal. • We have had success with the treatments we use. I wouldn’t want to rank them in order. The one course mill and resur- faces and concrete pavement repairs are “high end” fixes for CPM and work well with more distressed pavements. Surface sealing (crack seals, chip seals, micro, ultra-thin HMA) are successful at sealing the pavement and extending service life. • Open graded friction course. Lasts a long time when put on AC in good condition. • Mill, asphalt rubber crack relief layer and HMA overlay. • Thin HMA overlay, 40 mm. Most widely used, looked at as most failure proof. Known treatment, inspires confidence. • HMA overlay >1.5 in. but <2.00 in. We don’t place overlays less than 1.5 in. on our high-volume roads. These overlays are successful because they do add some structure back to the pavement. Therefore they may not be considered as pre- ventive maintenance by some. • Microsurfacing (single or multiple). Avoids ADA requirements. Often “misused” as a band-aid to avoid ADA or com- bined sewer issues that must be addressed with a higher level of treatment. • Mill and hot-mix overlay. • Crack filling. Reduces infiltration of moisture into the pavement structure and slows the rate of pavement deterioration. • Drainage preservation. Important to maintain adequate drainage. • Thin asphalt overlays. Lower cost and longer life than microsurfacing. Longer life than seals. Improves ride quality. • Chip seals. Very cost-effective method of pavement overlay, extends the life of existing road surface, seals and prevents moisture penetration and is a method that we can accomplish with our own forces. • Chip sealing. We do not chip seal routes with the extreme high volumes (i.e., 50,000 ADT). However, we have been suc- cessful chip sealing roads in the 4,000 to 5,000 ADT range. The costs for chip sealing are relatively low and the perfor- mance has been good. There is generally good availability of contractors to complete the work and the use of chip sealing is well established; dating back 40 or more years. • Ultra-thin (NovaChip). With increased use, process is now competitive. • Microsurfacing. MN/DOT has spent a large amount of time developing microsurfacing, which include strong specifi- cations, improved methods and training. 147

• Thin HMA overlay extends surface life. • Thin SMA overlay. Rut resistant, long lived. • Crack seal. Best in conjunction with a chip seal. • Slurry seal. Inexpensive, fast application. • Overlay with HMA 1.5 to 2 in. Successful due to good durability if existing surface is not deteriorated. • Microsurfacing. Fills minor rutting, restores friction, good overall performance, and rapid construction. • Ultra-thin bonded wearing course (AR, polymer). • Deep base patching. Spot repair of base failures in roadway. • Microsurfacing. Candidate selection thru PMS. Warranty by contractor, good QA process. Conscientious contractor. • Graded aggregate seal. Not chip economic and works. • Diamond grinding of PCC. Life of treatment exceed expectations. • Fine graded polymer AC OL (0.75 in.). Decent life extension for the cost. • Crack sealing. First action taken on a newer overlay to keep the water out and prevent the cracks from getting wider and depressing due to stripping of the asphalt. • Cold milling and HMA overlay. • Mill and overlay. • Profile milling diamond grinding. • Patching. • Cold milling. Cost-efficient, good restoration of the pavement, impact on life of pavement. • Microsurfacing/NovaChip. Restore skid numbers. Provide protection and wearing surface. • Microseal. Durable, quick to open to traffic. • Microsurfacing. Restores ride/comfort, seals minor cracking, fills ruts, opens up quickly to traffic. • Full/partial depth concrete patching. Prevents additional deterioration. • Single micro. Good experience for rut control. • Microsurfacing. Economical for relieving surface distress without major repairs. • 2 in. min. overlay. OK in cases where there is sound base and little or no rutting. • Microsurface. Provides friction course and rut repair. • Graded aggregate seal coat. Seals cracks. Low cost. Can be done in-house or contracted out. • 1.8 in. inlay on HMA. • Spray patching. Can seal and repair deteriorated transverse (low temperature) cracks for 2–3 years when workmanship is good. • Chip seal and high float. This is really the only true preservation technique that we have historically applied and again success is anecdotal and not robustly monitored as part of a preservation program. Applicability of chip seals on HMA is variable throughout the state as some areas are unacceptable candidates due to unstable foundations (permafrost) and high rates of rutting due to surface wear and studded tire action. • Diamond grinding. Although we have very little concrete pavement, much of it is on our parkway system, which does not carry extremely high volume of traffic. When pavements are ground in a timely manner, we can retard deteriora- tion and delay costly repairs. • Chip seals. Significant experience within CDOT maintenance forces. • Crack seal. Very effective in keeping water out. • Mill and fill. Agency and contractor experience and comfort level. Treatment 3 • Thin overlay (<60 mm). Thin overlays are placed on pavements that are 12–15 years old and show little or no fatigue cracking. MDT estimates that the life of a 20-year design HMA pavement can be extended to around 30 years with regu- larly scheduled pavement preservation treatments. • Microsurfacing. Relatively inexpensive compared to added life. • Flush seal. • We have had success with the treatments we use. I wouldn’t want to rank them in order. The one course mill and resur- faces and concrete pavement repairs are “high end” fixes for CPM and work well with more distressed pavements. Surface sealing (crack seals, chip seals, micro, ultra-thin HMA) are successful at sealing the pavement and extending service life. 148

• Microsurface. Extends life, seals cracks, fills some ruts. • HMA overlay. • Multiple-course microsurfacing. Best value for surface sealing. • Crack sealing and crack filling. We have had good success with rubberized materials applied in an overbanding tech- nique. We have used this material on both asphalt and PCC pavements. • Ultra-thin bonded wearing course. Same as microsurfacing above. • Microsurfacing. We have a warranty spec for microsurfacing that the districts like to use. • Microsurfacing. This treatment extended the life of some pavements that were beginning to exhibit premature sur- face deterioration. • Microsurfacing. It is a proven preservation treatment. • Ultra-thin asphalt overlays. • Slurry or microsurfacing. Provides a moisture barrier, improved riding surface, and extends life of existing roadway structure at a price less than conventional asphalt paving. • Thin overlays. Although higher in costs than some other preservation treatments, the improved smoothness, durabil- ity, nighttime construction option, and longer construction season that these treatments offer has made them a suc- cessful alternative in some locations. • Microsurfacing. Beginning to reuse this treatment this year. • Ultra-thin bonded wearing. MN/DOT has built many test section over the last 10 years and performance has been great. MN/DOT will use the model to promote UTBWC. • Ultra-thin HMA <.75 in. extends surface life. • Crack seal and fill. Keep water out, extend life. • 1.5 in. HMA overlay. Best for lane leveling. • Chip seal. Inexpensive, problems with chip loss. • Diamond grinding. Increase in ride quality while improving the life of pavement by decreasing dynamic loading. • Diamond grinding. • Spot strip sealing. Spot treatments to prevent base failures. • Rout and seal: Provincial crew. Used on young pavements 1–3 years old; Long history of use. • Thin overlay. Good strategy but costs are high. • 1.5 in. HMA mill and fill. • Microsurfacing. Decent life extension for the cost. • 2 in. hot in-place recycling with a polymer-modified chip seal. 100% recycle of the current surface and the seal doesn’t raise the grade of the roadway very much. Don’t have to overlay the shoulder is the road has them. • Full-depth concrete patching. • Thin-bonded wearing course and 1.5-in. overlays. Good functional benefits. • Cold mix. Cost-efficient, restoration of the surface. • Diamond grinding. Reduce dynamic loading. • Thin HMA overlay. Open graded friction course (rubber). • Overlays. Adds structural strength, corrects surface defects such as deep rutting and minor cracking and extends pave- ment life. • Microsurfacing. Reduces ruts and seals surface, improves ride. • Cape seal. Good fix for curbed area to maintain drainage control. • Crack sealing. Economical preventative measure to prolong pavement life. • Chip seal. Where pavement is sound except some cracking not subject to crack seal. • Crack seal. Decrease water infiltration into base. Buys time. • Microsurfacing (two passes: first for rutting and second for overall). Fills ruts, improves ride, low cost. • Dowel bar retrofit. Early dowel bar retrofits where done on highway segments with significant faulting, and gave 10–15+ years additional life. We expect at least as much from highway segments with aggregate interlock just failing. • “Blow and fill” crack sealing using rout and seal crack sealer but without rutting has been found cost-effective and bet- ter sealant performance than crack filler. • Double lift microsurfacing. We have very little experience with this application, and have just completed our first proj- ect on one of our parkways. So far it appears to be doing well, but it is too early to judge for certain. • Ultra-thin HMA overlay. Provides the most cost-effective treatment. • Crack sealing. Agency experience and comfort. Inexpensive. 149

Question 12 Please list the three MOST successful pavement preservation treatment types used on your URBAN high-traffic-volume road- ways, starting with the most successful, and briefly explain why each treatment is successful for your agency. Treatment 1 • Crack seal. MDT has aggressively sealed cracks for about 8–9 years. Keeping water out of the base and subgrade has improved performance. Of course timing is critical. MDT tries to make sure that all cracks are sealed prior to placing a chip seal. • Bituminous resurfacing. Relatively less risk, 8–12 years life. • NovaChip. Long-lasting treatment. • Microsurfacing. • We have had success with the treatments we use. I wouldn’t want to rank them in order. The one course mill and resur- faces and concrete pavement repairs are “high end” fixes for CPM and work well with more distressed pavements, which is often the case with urban high-traffic roadways. Surface sealing (crack seals, micro, ultra-thin HMA) are successful at sealing the pavement and extending service life. Chip seals are not used on urban high-volume routes. • Dowel bar retrofit. Extends the life of our old jointed plain concrete pavements. • Mill and HMA overlay. • Crack sealing. Best value for the cost, first line of defense in pavement preservation, retards future deterioration. • Mill and fill with HMA overlay >1.5 in. but < 2.00 in. • HMA mill/fill. • Thin hot-mix overlay. • 1 in. rubber modified AC overlay has allowed the asphalt to remain flexible and strong given our extremely high tem- peratures. • Crack sealing. It keeps moisture out of the pavement structure. This moisture can cause stripping in HMA pavements as well as localized pavement failure due to wet subgrades. • Crack seal/fill. Studies prove this treatment extends the life of the pavement if treatment applied at the right time. • Milling with thin asphalt overlay. Removes surface distresses, improves ride, preserves geometrics. Lower life-cycle cost than other treatments. • Cold milling and HMA overlays. Removes alligator cracked and oxidized surface, and reuses it in recycle mix to provide lower cost. Provides method to improve roadway cross section and maintain existing drainage elevations. • Mill and overlay. On our very high-volume routes (i.e., 50,000 ADT), this is the treatment of choice due to reduced dis- ruption to traffic (because of allowance for nighttime construction). Additionally, milling allows for minimal elevation changes where existing features such as curb and gutter exist. Smoothness can also be improved with this treatment. • Cold plane and overlay. Large number of experienced contractors. • Chip sealing. MN/DOT has spent a large amount of time developing better methods, specifications, and training on chip sealing. • Paver-placed elastomer surface treatment. Retards cracking. • Cold milling, HMA overlay <1.5 in. for rutting. • Chip seal with flush coat. Lower cost, reasonable service life. • Bonded wearing course. Holds up better then chip seal under high traffic. • Microsurfacing. • Mill and overlay with HMA 1.5 to 2 in. Successful due to good durability and experienced contractors. • Mill and 2 in. pavement. Often mill into curb and gutter only, with little or no milling at center line. Restores surface without a grade change. • Diamond grinding. • Mill/inlay. Provides better joints on these high-volume roadways. • Rubberized slurry seal. Familiar with its limits, increased longevity compared to conventional slurry seal. • Seal coat: Long history of good performance, >35 years. Candidate selection criteria through PMS. Excellent QA process, 2 provincial crews (in house). • Crack seal. • Diamond grooving of PCC. Life of treatment exceeded expectations. 150

• Thin HMA OL (2 in. or less). Capable of adding structure. • PCCP patching, diamond grinding, and resealing joints on PCCP. Reestablishes the ride quality of a deteriorated con- crete pavement. • Thin HMA overlay. • Thin lift overlay. • Cold milling and HMA overlay 1.5 in. • Crack sealing. • Cold milling and HMA. Cost-efficient, good restoration of the pavement, impact on life of pavement. • Crack and joint sealing. First step in pavement preservation. Keep the water out. • Thin HMA overlay (rubber). Noise reduction. • Milling and hot-mix inlay/overlay. Removes upper layers of deteriorating pavement, corrects surface defects, main- tains vertical alignment with curb and gutter. • Crack fill/seal. Keeps moisture out. • 4 in. whitetopping. Cost-effective long-term fix. • Cold milling/overlay. Ability to reuse milled pavement in recycled mix. Able to remove surface distress while strength- ening road. • Cold milling and overlay at least 2 in. Restores pavement section and eliminates variation of compaction due to rutting. • Microsurface. Good for rutting and increased friction. Also good in C&G areas (thin lift). • Dowel bar retrofit. • Ultra-thin whitetopping for rutted intersection has been used once very successfully (we have very little urban road). • Overlays and mill and overlay are the most widely used most successful in extending remaining service life. Again, we do not yet have a robust monitoring program other than pavement management’s automated collection of IRI and rut- ting data. • Cold mill and 1.25 in. to 1.5 in. HMA. Much of our urban areas require milling in order to maintain grade for curb and gutter sections. Contractors and agency personnel have experience with this treatment, and there is generally good com- petition in the urban areas. • Crack sealing. Significant experience within CDOT maintenance forces. • Thin HMA overlay. • 1.5 in. HMA overlay with shim. Experienced contractors and agency personnel. It’s a known material. Treatment 2 • Chip seal. MDT places chip seals on pavements that are 5–7 years old (time since last overlay or rehabilitation). This has been a very effective treatment. • Crack sealing. Inexpensive, prolongs life of surface. • Roadarmor. Preserve pavement for long time. • Flush seal. • We have had success with the treatments we use. I wouldn’t want to rank them in order. The one course mill and resur- faces and concrete pavement repairs are “high end” fixes for CPM and work well with more distressed pavements, which is often the case with urban high-traffic roadways. Surface sealing (crack seals, micro, ultra-thin HMA) are successful at sealing the pavement and extending service life. Chip seals are not used on urban high-volume routes. • NovaChip. Have used this successfully on AC and PC pavements. • Mill, asphalt rubber crack relief layer and HMA overlay. • Thin HMA overlay, 40 mm most widely used, looked at as most failure proof. Known treatment, inspires confidence. • HMA overlay >1.5 in. but <2.00 in. • Microsurfacing. • Partial depth repairs. Have been very successful in spall and joint repairs. We use a lot of polymer modified concrete. • Crack filling. Reduces infiltration of moisture into the pavement structure and slows the rate of pavement deterioration. • Drainage preservation. Important to maintain adequate drainage. • Thin asphalt overlays. Lower cost and longer life than microsurfacing. Longer life than seals. Improves ride quality. • Microsurfacing. Very quick method to address cracking, rutting, improving roadway profile and drainage at a cost less than traditional HMA overlays. 151

• Cold in-place recycling with an overlay. Note: We do not consider this a preservation treatment but rather a cost effec- tive rehabilitation. These treatments have had outstanding performance for us. With a 3 to 4 in. recycling depth and a designed overlay thickness (typically 2 to 4 in.), we have achieved in access of 20 years of performance life. Additionally, the reliability of this treatment has been very good. We have not experienced any significant premature failures with this treatment. • PCC patching and joint work. Have good details and a few experienced contractors. • Microsurfacing. MN/DOT has spent a large amount of time developing microsurfacing which include strong specifica- tions, improved methods and training. • Thin SMA overlay. Rut resistant, long lived. • Crack seal. Takes care of small cracks. • Open grade surface course (OGSC). Spray during rain. • Overlay with HMA 1.5 to 2 in. Successful due to good durability if existing surface is not deteriorated. • Microsurfacing. Fills minor rutting, restores friction, good overall performance, and rapid construction. • Thin HMA overlays. • Crack filling/sealing. Detour water from base. • Microsurfacing. Candidate selection thru PMS. Warranty by contractor, Good QA process. Conscientious contractor. • Thin overlay. • Diamond grinding of PCC. Life of treatment exceed expectations. • Fine graded polymer AC OL (0.75 in.). Decent life extension for the cost. • Ultra-thin bonded wearing course (NovaChip). It is a seal and hot-mix overlay in one and improves ride quality while sealing the water out, reduces water spray, and skid resistance of surface on either PCCP or asphalt roadways. • Cold milling and HMA overlay. • Mill and overlay. • Crack seal. • Patching. • Cold mix. Cost-efficient, restoration of the surface, quickly to put in place. • Microsurfacing/NovaChip. Restore skid numbers. Provide protection and wearing surface. • Fog seal. Inexpensive, retards oxidation. • Hot-mix overlay. Adds structural strength, corrects surface defects such as deep rutting and minor cracking and extends pavement life. • Full/partial-depth concrete patching. Prevents additional deterioration. • Two-course micro. • Microsurfacing. Economical for relieving surface distress without major repairs. • 2 in. min. overlay. OK in cases where there is sound base and little or no rutting. • HMA. Less customer complaints due to low noise. • HMA overlay. • Crack seal/fills. This is our most prevalent preservation technique, but success is anecdotal. We do not monitor for crack- ing in pavement management. • 1.25 in. to 1.5 in. HMA. Where milling is not necessary, a thin asphalt surface has been the primary treatment on urban roads. The ability of our forces to maintain asphalt pavements is one of the primary reasons for the widespread use of this treatment. • PCCP panel repairs, includes crack sealing, dowel bar retrofit, partial panel replacement. • Crack seal. • Mill and fill. Agency and contractor experience and comfort level. Treatment 3 • Thin overlay (<60 mm). Thin overlays are placed on pavements that are 12–15 years old and show little or no fatigue cracking. MDT estimates that the life of a 20 year design HMA pavement can be extended to around 30 years with regu- larly scheduled pavement preservation treatments. • Microsurfacing. Relatively inexpensive compared to added life. • Italgrip, Increased the surface friction. 152

• Chip seal. • We have had success with the treatments we use. I wouldn’t want to rank them in order. The one course mill and resur- faces and concrete pavement repairs are “high end” fixes for CPM and work well with more distressed pavements, which is often the case with urban high-traffic roadways. Surface sealing (crack seals, micro, ultra-thin HMA) are successful at sealing the pavement and extending service life. Chip seals are not used on urban high-volume routes. • Thin overlays. Restores ride and extends life. • HMA overlay. • Tie: Multiple-course microsurfacing—best value for surface sealing; and thin-bonded overlay—quick time to resume normal traffic. • Crack sealing and crack filling. We have had good success with rubberized materials applied in an overbanding tech- nique. We have used this material on both asphalt and PCC pavements. • Ultra-thin bonded wearing course. • Full-depth repairs. Special attention is needed during construction for installation of the dowel bars, and type of epoxy used. • Microsurfacing. This treatment extended the life of some pavements that were beginning to exhibit premature sur- face deterioration. • Microsurfacing. It is a proven preservation treatment. • Ultra-thin asphalt overlays. • Thin HMA overlays, which add structural value to road, improving drainage profile, rideability, and moisture penetration. • Thin overlays. Although higher in costs than some other preservation treatments, the improved smoothness, durabil- ity, nighttime construction option, and longer construction season that these treatments offer has made them a suc- cessful alternative in some locations. • Ultra-thin bonded wearing. MN/DOT has built many test sections over the last 10 years and performance has been great. MN/DOT will use the model to promote UTBWC. • Crack seal and fill. Keep water out, extend life. • HMA overlay. Makes the ride smoother. • Mill and overlay with HMA 1 to 1.5 in. Successful due to less cost but with less expected life than thicker overlays. • Isolated full-depth fast-setting hydraulic cement repairs (slab replacement with rapid strength concrete). Min. strength 400 PSI. • Deep base patching. Spot repair of base failures in roadway. • Rout and seal: Provincial crew. Used on young pavements 1–3 years old. Long history of use. • Hot in-place recycling. • 1.5 in. HMA mill and fill. • Microsurfacing. Decent life extension for the cost. • Mill and inlay of asphalt surface. Milling supply’s a source of quality RAP for up to 25% recycling and doesn’t raise the grade of the roadway so we don’t have to overlay the shoulders of they are in okay condition. • Full-depth concrete patching. • Thin-bonded overlay and 1.5-in. overlays. • Diamond grinding. Reduce dynamic loading. • Microseal. Durable and quick to open to traffic. • Heater scarification and overlay. Removes and rejuvenates upper layers of deteriorating pavement, corrects surface defects, improves riding quality, opens up quickly to traffic. • Microsurfacing. Reduces ruts and seals surface, improves ride. • Polymer chip seal. • Crack sealing. Economical preventative measure to prolong pavement life. • Cold milling to daylight ruts on sound pavement and remove standing water. This is only done because our milling machines produce very fine textured surface that doesn’t do much to change noise levels and maintains good skid numbers. • HMA inlay. • Chip seal and high float. This is really the only true preservation technique that we have historically applied and again success is anecdotal and not robustly monitored as part of a preservation program. Applicability of chip seals on HMA is variable throughout the state as some areas are unacceptable candidates due to unstable foundations (permafrost) and high rates of rutting due to surface wear and studded tire action. 153

• Diamond grinding. Some of our urban areas have large concentrations of concrete pavements on the Interstate system. Diamond grinding provides a way to lengthen the life of these pavements before more costly repairs are needed. • Ultra-thin overlay. • Crack sealing. Agency experience and comfort. Inexpensive. Question 13 Please list the three LEAST successful pavement preservation treatment types used on your RURAL high-traffic-volume road- ways, starting with the most successful, and briefly explain why each treatment is successful for your agency. Treatment 1 • Occasionally chip seals placed on high-volume routes will bleed due to poor construction practices or mix design. This occurs on approximately 5% or less on chip seal projects. • Unknown, unsuccessful treatments done in the past are no long practice. • If the right fix is done on the right road the treatment should be successful. Anything that is less effective I wouldn’t attribute to the fix itself. • Joint rehab on dowel mesh reinforced concrete pavement. Ride is still impaired. • Thin concrete overlay. Poor performance and high cost. • We don’t use unsuccessful treatments. We have had performance problems with most of the treatments that we still use. • NovaChip. I think the road was probably too far gone to be a good candidate. Crack reflected back through the surface in a short amount of time. • Chip seal. Dust, bleeding, loose chips. • Chip seals. Loose rock hitting windshields, flushing issues. • Partial-depth patching. Patches did not perform as well as expected. • Unable to rate unsuccessful treatments as our efforts focus are towards successful treatments. • Ultra-thin PCC overlays. Problems with bonding, early failures and expensive. • Fog seal. Reduced skip resistance. • When treatments are not successful it is usually not the treatments fault. Rather it’s generally due to poor treatment selec- tion, poor construction quality, or poor timing. Of the treatments we use, we do not have any labeled as “unsuccessful.” We have had problems with all of our treatments at one time or another, due to reasons stated in the first sentence, but nothing systemic. • Chip seals. Tend to lose rock and break windshields; tend to ravel; proper construction techniques are sometimes lacking. • Crack sealing has had more failures than are acceptable. • Profile milling. Some locations have produced less than desirable surface conditions. • Slurry seal. Short lived. • Chip seal. Loss of chips—raveling. • Crack sealing on PCC pavements with basic asphalt based sealants. High labor costs with little increase in pavement life. • Chip seals. Chip loss bleeding and early failures. High degree of failure risk. Have had some catastrophic failures with chips and emulsion not curing properly and rolling up on tires. • Calcium chloride PCC slab replacement (because of low strength) slow setting. • Rubberized slurry seal. Familiar with its limits, increased longevity compared to conventional slurry seal. • Crack sealing. When certain products are found to be ineffective. Only approved products are currently used that have demonstrated performance. Problem with what to do with rout and crack seal after life cycle. • Cold in-place. Expensive and does not work well. • NovaChip. Too expensive. • Nothing: We have been at this a long time and so we know by now what we don’t want to use. • DMR product. Total failure. Had to mill off roadway and overlay with HMA. Probably placed when weather was too cold for successful application. Resulted in never to be used again. • No other tried this district. • Single-course chip seal. • Do nothing. 154

• Crack filling. Cost-efficient, easy to realize, performance. • Chip sealing. Failure of chip seals resulting in lower skid numbers and vehicle damage from flying rock. • Chip seal, single app. Rock damage. • Cold recycling. Comes apart. • Chip seal. Does not hold up under traffic. • Thin overlays. Reflective cracking. • Microsurface. Cost is about the same as a 1.5 in. overlay and does little or nothing for strength. • HMA. Cost. Some of our districts use this treatment to raise their ride score, but it is not cost-effective. • Rubber crack fill. Lack of follow-up treatment after failure. • Crack sealing using cold pour materials does not last more than one season. Seems to help prevent spalling at the crack but does not provide lasting seal to moisture infiltration. • Chip seal. We had several chip seal projects that were considered failures by the public and agency officials. This treat- ment has a very poor reputation in the state. • Hot in-place HMA recycling. Durability was low. • Microsurfacing. Doesn’t stand up well to aggressive snow plowing. Treatment 2 • If the right fix is done on the right road the treatment should be successful. Anything that is less effective I wouldn’t attribute to the fix itself. • CPR on dowel mesh reinforced concrete pavement. Ride is still poor. • Chip seal. Noisy, cracked windshields, short life. • We do not use fog seals and rejuvenators on travel lanes due to possible friction problems. • Chip seal. Traffic, especially trucks, dislodged most of the aggregate in several weeks. This was on an Interstate route and was done back in the mid 1980s. This experience has kept us from considering using chip seal on high-volume roads even though the new polymer-modified emulsions will probably perform better. • Cold in-place recycling (stripping issues). • Chip seals. Our design and construction staffs have limited experience with chip seals. Therefore, they are sometimes placed with excess cover aggregate, which results in damage to vehicles. • Microsurfacing. Not much of an advantage over seals and much more expensive. Life expectancy about the same as seals. • Hot in-place recycling. A lack of material consistency incorporated into the finished mat because of the presence of joint and crack seal material. • Partial-depth PCC repairs. Due to high rate of subsequent failures. • 1 in. or 1.5 in. overlays. Consider theses as reactive maintenance to address a problem until a rehab can be performed. Chance of success and life of overlay greatly increases with 2 in. lifts. • Chip seal. Windshield damage. • Hot in-place recycle. This section of roadway had to be milled and overlaid with HMA failure. • Ultra-thin HMA overlay <.75 in. • Chip seals. Poor surface characteristics and short life. • Cold milling and HMA. Cost-efficient, good restoration of the pavement, impact on life of pavement. • Thin overlay. Less than 3.75 in. Any thinner provides insufficient structural improvements and increases failure. • Chip seal double app. Rock damage. • Partial- and full-depth concrete slab repairs. Too expensive and takes too long. • Slurry. Does not hold up. • Chip seal. Public perception and opinion. • Slurry seal. Only good to seal cracks, no strength added. Cost is important. • Microsurface. Although we have great success with this treatment, we still have districts using it on roadways with bad FWD [falling weight deflectometer] numbers. • Conventional crack fill. Short life due to changing seasons. • Microsurfacing has been used on selective basis and has tended to wear off within about 3 years. We have since moved to a thicker application and larger top size. 155

• Partial-depth concrete patching. We have found that the cost of partial-depth patching was not significantly less than full-depth patching and therefore did not provide adequate savings to justify its use. • Single-course chip seal. Durability was low. • Rubber chip seal. Snowplow damage. Agency and contractor inexperience. We had to get out of state contractor to pro- duce and lay down. Aggregate provided by local contractor. Treatment 3 • If the right fix is done on the right road the treatment should be successful. Anything that is less effective I wouldn’t attribute to the fix itself. • Bonded overlay. Had early cracking. • Microsurfacing. High cost, short life, rapid deterioration requiring quick repair. • We do not use cold-in-place recycling on high-volume pavements due to traffic control issues and possible per- formance problems. • Crack sealing. Usually just causes bumps and car paint problems. • Joint and crack seal/fill, because of poor adhesion to the crack walls. • Full-depth PCC repairs. These will work well but we have a history of diminished ride quality due to poor grade control. • Slurries and fogs don’t work. • Hot in-place HMA. We use 2 in. hot in-place with an overlay. • Cold in-place recycle. Rough ride and long cure time. • Concrete. • HMA less than .75 in. Durability. • Cold-in-place recycling. The cost of mobilization (equipment and contractor) for small projects. • Fog seal. There is an issue with traffic and curing time. The best time to apply is when crews are too busy with other work. In the off-season, curing time is long and an inconvenience to traffic and workers. • Route and seal for cracks has been “hit and miss” for performance and when we have large amounts of sealant loss it creates a bigger problem than we started with. Question 14 Please list the three LEAST successful pavement preservation treatment types used on your URBAN high-traffic-volume road- ways, starting with the most successful, and briefly explain why each treatment is successful for your agency. Treatment 1 • Occasionally chip seals placed on high-volume routes will bleed due to poor construction practices or mix design. This occurs on approximately 5% or less on chip seal projects. • If the right fix is done on the right road the treatment should be successful. Anything that is less effective I wouldn’t attribute to the fix itself. • CPR without DBR on jointed concrete pavement. Ride still poor. • Microsurfacing. High cost, short life, rapid deterioration requiring quick repair. • We don’t use unsuccessful treatments. We have had performance problems with most of the treatments that we still use. • No horror stories to report here. • Chip seals, loose rock hitting windshields, flushing issues. • Partial-depth patching. Patches did not perform as well as expected. • Unable to rate unsuccessful treatments as our efforts focus toward successful treatments. • Ultra-thin PCC overlays. Problems with bonding, early failures, and expensive. • When treatments are not successful it is usually not the treatments fault. Rather it’s generally due to poor treatment selection, poor construction quality, or poor timing. Of the treatments we use, we do not have any labeled as unsuc- cessful. We have had problems with all of our treatments at one time or another, due to reasons stated in the first sen- tence, but nothing systemic. • Crack sealing has had more failures than are acceptable. 156

• Microsurfacing. Too brittle. • Profile milling. Some locations have produced less than desirable surface conditions. • Slurry seal. Short lived. • OGSC. Increased stripping issues, raveling. • Partial-depth PCC repairs. Due to high rate of subsequent failures. • Chip seals. Same as rural accept closure time and traffic issues play a larger role. • Calcium chloride PCC slab replacement (because of low strength) slow setting. • Rubberized slurry seal. Familiar with its limits, increased longevity compared to conventional slurry seal. • Crack sealing. When certain products are found to be ineffective; only approved products are currently used that have demonstrated performance; problem with what to do with rout and crack seal after life cycle. • Chip seals. Windshield damage and noise and rough road surface. • NovaChip. Too expensive. • Thin HMA overlays over PCCP. They don’t last very long and have a tendency to debond and spall out in the winter. • No other tried this district. • Single-course chip seal. • Do nothing. • Crack filling. Cost-efficient, easy to realize, performance. • Chip sealing. Failure of chip seals resulting in lower skid numbers and vehicle damage from flying rock. • Chip seal, single app. Rock damage. • Chip seals. Chips come loose with high-volume, high-speed traffic. • Chip seal. Does not hold up under traffic. • Thin overlays. Reflective cracking. • Microsurface. No strength added. • Seal coat. In areas where there is a lot of traffic turning movement. • Partial-depth concrete patching. We have found that the cost of partial-depth patching was not significantly less than full depth patching, and therefore did not provide adequate savings to justify its use. • Hot in-place HMA recycling. Treatment 2 • If the right fix is done on the right road the treatment should be successful. Anything that is less effective I wouldn’t attribute to the fix itself. • Very thin AC overlays (1 in. or less). Rutting comes back too quickly. • Hot in-place. Short life, high chance for failure. • We do not use fog seals and rejuvenators on travel lanes due to possible friction problems. • Skidabrader if aggregates are soft the restored skid will go down quickly. • Thin HMA overlays. In urban applications, with slow moving traffic/trucks, these overlays can sometimes rut and shove. • Microsurfacing. Not much of an advantage over seals and much more expensive. Life expectancy about the same as seals. • Full-depth PCC repairs. These will work well but we have a history of diminished ride quality due to poor grade control. • Thin overlays. 1 in. or 1.5 in. overlays. Consider these as reactive maintenance to address a problem until a rehab can be performed. Chance of success and life of overlay greatly increases with 2 in. lifts. • Fog seal. • Ultra-thin HMA overlay <.75 in. • Microsurfacing. Poor surface characteristics. • Cold milling and HMA. Cost-efficient, good restoration of the pavement, impact on life of pavement, restoration of sur- face characteristics. • Thin overlay. Less than 3.75 in. Any thinner provides insufficient structural improvements and increases failure. • Chip seal, double app. Rock damage. • Slab jacking. Slabs rose unevenly. • Slurry. Does not hold up. 157

158 • Chip seal. Public perception and opinion. • Slurry. No strength added. • Microsurface. In areas with bad FWD [falling weight deflectometer] numbers. • Single-course chip seal. Treatment 3 • If the right fix is done on the right road the treatment should be successful. Anything that is less effective I wouldn’t attribute to the fix itself. • Microsurface. Doesn’t last long enough. • Thin HMA overlay of deeply cracked pavement. Quick reflection of cracks. • We do not use cold in-place recycling on high-volume pavements due to traffic control issues and possible performance problems. • Crack sealing. Usually just causes bumps and car paint problems. • Microsurfacing. • Hot in-place HMA. We use 2 in. hot in-place with an overlay. • Cold in-place recycle. Rough ride and long cure time. • Partial- and full-depth concrete slab repairs. Too expensive and takes too long. • HMA less than .75 in. Durability. • Cold in-place recycling. The cost of mobilization (equipment and contractor) for small projects. • Thin overlays. Not enough strength added. Question 15 Available facility closure time is an important consideration when selecting the most appropriate treatment for a pavement sec- tion. Please use the following to indicate under which of the following available closure time scenarios you consider using the listed treatments on RURAL roadways. Tables C.17 and C.18 present the agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included.

159 Table C.17. Summary of Closure Time Scenarios Considered When Using a Preventive Maintenance Treatment for RURAL High-Traffic-Volume HMA Roads Overnight OR HMA-Surfaced Pavement Treatments Single Shift Weekend Longer Number of for High-Traffic-Volume Roadways % Response % Response % Response Respondents Crack fill 95 19 16 43 Crack seal 96 19 15 47 Cape seal 100 22 6 18 Fog seal 92 12 15 26 Scrub seal 87 13 20 15 Slurry seal 89 21 14 28 Rejuvenators 89 16 16 19 Single-course microsurfacing 95 24 15 41 Multiple-course microsurfacing 86 23 20 35 Single-course chip seal 95 8 11 37 Multiple-course chip seal 88 9 12 32 Chip seals with polymer-modified asphalt binder 94 12 9 32 Ultra-thin bonded wearing course (e.g., NovaChip) 92 22 17 36 Thin HMA overlay (<40 mm [<1.5 in.]) 90 18 18 40 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 85 21 21 39 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 85 15 19 26 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 76 12 24 25 Cold-in-place recycling (<100 mm [<4.0 in.]) 72 17 31 29 Profile milling (diamond grinding) 84 24 12 25 Ultra-thin whitetopping 42 27 54 26 Drainage preservation 93 22 22 27 Other (see below) 100 0 0 2 Note: Overnight (e.g., from 10 p.m. to 6 a.m.); Single Shift (e.g., 9 a.m. to 4 p.m.); Weekend (e.g., from 8 p.m. on Friday to 5 a.m. on Monday); Longer (longer than 2 days). Agency Comments (Table C.17): • Rubberized chip seal. • Normally allow a long working day (7:00 a.m.–7:00 p.m.). Roadway must be open at night. • 1.5 in. HMA mill and fill. • Closure time is low priority in Manitoba. • Ultra-thin whitetopping (major rehabilitation). • Traffic accommodation is provided virtually 100% of the time. Not a significant factor in the Preservation “Decision Tree.”

160 Table C.18. Summary of Closure Time Scenarios Considered When Using a Preventive Maintenance Treatment for RURAL High-Traffic-Volume PCC Roads Overnight OR PCC Pavement Treatments for Single Shift Weekend Longer Number of High-Traffic-Volume Roadways % Response % Response % Response Respondents Concrete joint resealing 85 30 22 40 Concrete crack sealing 85 25 22 40 Diamond grinding 85 30 28 40 Diamond grooving 89 19 15 27 Partial-depth concrete pavement patching 68 38 38 40 Full-depth concrete pavement patching 70 44 44 43 Dowel bar retrofit (load-transfer restoration) 70 42 39 33 Thin PCC overlays 35 30 57 23 Ultra-thin bonded wearing course (e.g., HMA < 25 mm [1 in.]) 82 23 9 22 Thin HMA overlay (<40 mm [<1.5 in.]) 81 15 11 27 Drainage preservation 90 31 14 29 Other (see below) 50 50 0 2 Note: Overnight (e.g., from 10 p.m. to 6 a.m.); Single Shift (e.g., 9 a.m. to 4 p.m.); Weekend (e.g., from 8 p.m. on Friday to 5 a.m. on Monday); Longer (longer than 2 days). Agency Comments (Table C.18): • The items marked overnight would be allowed a long working day. If they are performed in conjunction with slab repairs, longer closures are allowed. • Thin PCC overlays (major rehabilitation). Question 16 Please use the following to indicate under which of the following available closure time scenarios you consider using the listed treatments on URBAN roadways. Tables C.19 and C.20 present the agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included.

Agency Comments (Table C.19): • Rubberized chip seal. • Closure depends on number of lanes available and if there are increased levels of traffic at certain times. • 1.5 in. HMA mill and fill. • Ultra-thin whitetopping (major rehabilitation). 161 Table C.19. Summary of Closure Time Scenarios Considered When Using a Preventive Maintenance Treatment for URBAN High-Traffic-Volume HMA Roads Overnight OR HMA-Surfaced Pavement Treatments for Single Shift Weekend Longer Number of High-Traffic-Volume Roadways % Response % Response % Response Respondents Crack fill 95 21 12 42 Crack seal 96 23 11 47 Cape seal 87 20 7 15 Fog seal 85 20 10 20 Scrub seal 79 21 7 14 Slurry seal 78 26 9 23 Rejuvenators 82 24 6 17 Single-course microsurfacing 87 36 15 39 Multiple-course microsurfacing 84 34 16 32 Single-course chip seal 90 20 10 30 Multiple-course chip seal 85 22 7 27 Chip seals with polymer-modified asphalt binder 90 17 10 29 Ultra-thin bonded wearing course (e.g., NovaChip) 94 27 15 33 Thin HMA overlay (<40 mm [<1.5 in.]) 90 30 15 40 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 88 31 19 42 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 84 32 24 25 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 70 30 20 20 Cold-in-place recycling (<100 mm [<4.0 in.]) 67 38 25 24 Profile milling (diamond grinding) 88 36 16 25 Ultra-thin whitetopping 32 45 55 22 Drainage preservation 93 32 18 28 Other (see below) 100 0 0 2 Note: Overnight (e.g., from 10 p.m. to 6 a.m.); Single Shift (e.g., 9 a.m. to 4 p.m.); Weekend (e.g., from 8 p.m. on Friday to 5 a.m. on Monday); Longer (longer than 2 days).

Agency Comments (Table C.20): • Depends on lanes available. • Thin PCC overlays (major rehabilitation). Restrictions on construction time occur on extremely high-volume urban sections. Responses assume restrictions may occur on rural sections as well. Question 17 Please check any of the following contracting mechanisms that your agency uses to help ensure the quality and future perfor- mance of the following treatments on your high-traffic-volume roadways? Please check all that apply. Tables C.21 and C.22 present the agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included. 162 Table C.20. Summary of Closure Time Scenarios Considered When Using a Preventive Maintenance Treatment for URBAN High-Traffic-Volume PCC Roads Overnight OR Single Shift Weekend Longer Number of PCC Pavement Treatments for High-Traffic-Volume Roadways % Response % Response % Response Respondents Concrete joint resealing 92 30 12 40 Concrete crack sealing 92 32 15 40 Diamond grinding 95 36 13 39 Diamond grooving 91 30 4 23 Partial-depth concrete pavement patching 68 49 30 37 Full-depth concrete pavement patching 67 50 38 42 Dowel bar retrofit (load-transfer restoration) 65 44 44 34 Thin PCC overlays 39 30 57 23 Ultra-thin bonded wearing course (e.g., HMA < 25 mm [1 in.]) 87 26 4 23 Thin HMA overlay (<40 mm [<1.5 in.]) 88 20 8 25 Drainage preservation 93 30 19 27 Other (see below) 0 0 0 0 Note: Overnight (e.g., from 10 p.m. to 6 a.m.); Single Shift (e.g., 9 a.m. to 4 p.m.); Weekend (e.g., from 8 p.m. on Friday to 5 a.m. on Monday); Longer (longer than 2 days).

163 Agency Comments (Table C.21): • Rubberized chip seal. • 1.5 in. HMA mill and fill. • Ultra-thin whitetopping (major rehabilitation). Table C.21. Summary of Contracting Mechanisms Used to Ensure Quality for a Preventive Maintenance Treatment for High-Traffic-Volume HMA Roads Contracting Mechanisms Used HMA-Surfaced Pavement Treatments for Performance Contract Number of High-Traffic-Volume Roadways QC/QA Specifications Warranties Maintenance Respondents Crack fill 50 41 9 44 34 Crack seal 51 41 13 46 39 Cape seal 70 30 20 50 10 Fog seal 47 20 0 53 15 Scrub seal 55 18 0 55 11 Slurry seal 74 32 11 47 19 Rejuvenators 54 38 0 46 13 Single-course microsurfacing 57 38 27 38 37 Multiple-course microsurfacing 67 26 26 33 27 Single-course chip seal 67 42 21 45 33 Multiple-course chip seal 64 43 18 39 28 Chip seals with polymer-modified asphalt binder 60 40 13 40 30 Ultra-thin bonded wearing course (e.g., NovaChip) 67 39 12 30 33 Thin HMA overlay (<40 mm [<1.5 in.]) 84 44 23 37 43 Cold milling and HMA overlay (<40 mm [<1.5 in.]) 82 51 26 31 39 Ultra-thin HMA overlay (<20 mm [<0.75 in.]) 76 43 19 33 21 Hot in-place HMA recycling (<50 mm [<1.95 in.]) 72 40 12 36 25 Cold-in-place recycling (<100 mm [<4.0 in.]) 82 36 14 36 28 Profile milling (diamond grinding) 55 59 0 27 22 Ultra-thin whitetopping 67 33 6 28 18 Drainage preservation 73 23 5 41 22 Other (see below) 100 0 0 0 3

Agency Comments (Table C.22): • All concrete maintenance is performed by city crews. • Dowel bar retrofit (have standard specification—seldom used). Thin PCC overlay (major rehabilitation). Question 18 Does your agency have in place quality control/quality assurance (QC/QA) procedures for preventive maintenance applications? If “Yes,” would you describe these QC/QA procedures as informal or formal? Based on 57 total responses, the following percentages of “Yes” and “No” were observed: • Yes: 51% • No: 49% If the agency responded “Yes,” a follow-up question asks the respondent to, if possible, provide a copy of the procedures (by fax, e-mail, or URL link). • Yes: If put out to bid; No: If done with state forces. • http://www2.dot.state.fl.us/SpecificationsEstimates/Implemented/CurrentBK/Default.aspx?PageAddr=lt;a%20hrefeq;qt. • Maintenance applications are covered the same as pavement used for rehabilitation. • www.virginiadot.org/business/const/spec-default.asp. • http://mdotwas1.mdot.state.mi.us/public/dessssp/. • But only during placement. • Normal construction/material specifications. • Contractor needs ISO 9001 quality plan. • Internal QC. • 2006 LA Standard Specifications for Roads and Bridges; Materials Sampling Manual; Materials Testing Procedure Manual. www.dotd.la.gov/highways/project_devel/contractspecs/2006_STAND_SPECS.zip. • https://www.raqsa.mto.gov.on.ca/techpubs/ops.nsf/OPSHomepage. • www.ksdot.org. 164 Table C.22. Summary of Contracting Mechanisms Used to Ensure Quality for a Preventive Maintenance Treatment for High-Traffic-Volume PCC Roads Contracting Mechanisms Used Performance Contract Number of PCC Pavement Treatments for High-Traffic-Volume Roadways QC/QA Specifications Warranties Maintenance Respondents Concrete joint resealing 56 31 6 39 36 Concrete crack sealing 56 31 6 42 36 Diamond grinding 59 38 6 35 34 Diamond grooving 55 40 5 30 20 Partial-depth concrete pavement patching 59 22 6 44 32 Full-depth concrete pavement patching 58 29 8 39 38 Dowel bar retrofit (load-transfer restoration) 58 32 6 35 31 Thin PCC overlays 56 38 0 38 16 Ultra-thin bonded wearing course (e.g., HMA < 25 mm [1 in.]) 72 33 6 33 18 Thin HMA overlay (<40 mm [<1.5 in.]) 75 35 5 40 20 Drainage preservation 75 20 5 45 20 Other (see below) 100 0 0 50 2

As indicated by a “No” response to question 18, you do not currently have QC/QA procedures for preventive maintenance treat- ments in place. Do you have plans for implementing them? Based on 24 responses, the following percentages of “Yes” and “No” were observed: • Yes: 17% • No: 83% Individual statements included: • Several years ago, we had a QA procedure for several maintenance activities. These have since been discontinued. • Our maintenance forces complete most of the preventative maintenance items that have been discussed. • Contractor to have a quality management program in place. • We enforce QC/QA by using the Greenbook and our in-house materials laboratory. As indicated by a “No” response to question 18, you indicated that your agency does not use warranty specifications on any of your preventive maintenance treatments. Do you have any plans/interest in the use of warranties? Based on 23 responses, the following percentages of “Yes” and “No” were observed: • Yes: 26% • No: 74% Individual comments included: • 18 doesn’t say anything about warranties. We require warranties for microsurface and UBWC. • I am interested in looking at warranties on all four treatments that we allow, but no time frame as to when that would happen. • HMA overlays. Question 19 If you indicated that your agency has implemented performance-related specifications for preventive-maintenance treatments, briefly describe your experience with these specifications. • We get a better product from contractors with specs in force. • Mostly good experience. • Our current standard specifications were our first attempt at performance specifications. It is not entirely performance based. The next version will work toward more performance specs. So far the majority of work done by performance specification has been good. • We have a performance specification for chip seal, including conventional, polymer modified, fiberized, and rub- berized chip seals. The contracts include warranty provisions. The contracting community proposed them and they have been very cooperative in addressing the problems on a small percentage of completed projects. • Materials field testing of PG graded asphalt products as well as QA testing of the HMA. • Ride specification (IRI). Very good experience. • Good. If we have a problem such as not meeting density requirements, contractor is penalized or removed and replaced. • We have warranties on the majority of CPM projects, generally 2 years for surface seals and 3 years for HMA overlays. • Generally, we obtain good result, but sometimes, it is difficult to choose the right specification. • We do have performance-related specifications for pavements in our total maintenance contracts. We have revised them through the years based on experience and I believe that they are working well. • Good. • They define proper materials and processes but need to be revisited to address issues that arise. • These are specifications are more with performance, ride quality, etc. Our construction side of the house provides the inspection with these items. 165 Question 18 (continued)

• Warranties on chip seals. Volumetric Mix Design, Hamburg Rut Testing. • Chip seal and micro must meet 1-year review by agency. • We have 1- or 2-year warranties in place for many pavement preservation treatments. We are also trialing 3- and 7-year warranties for some pavement preservation treatments. • Our performance-related specifications are only with hot-mix asphalt applications. These specifications were not devel- oped specifically for preventive maintenance treatments but rather for overlays—both structural and thin PM overlays. We use the Superpave system with performance-graded binders, statistical acceptance for several key parameters, and incorporate pay factors. We also control the roughness using IRI and pay factors. We have been using these specifica- tions for over 10 years with good success. • The nationally certified Materials Lab for the City of Phoenix has a representative at a supply plant when a project is ongoing. The Materials Lab tests each sample to ensure that the mixes are within design specifications. • Mostly ride specs on multiple layer projects like a 2 in. SR and NovaChip for HMA or ride spec on diamond grinding and concrete inlay. • Generally the specifications represent procedures that have been proven to be successful over time. Materials and meth- ods have to meet these specs or be replaced by the contractor or supplier. • To my knowledge we only have performance related specs for microsurfacing. I am not familiar with spec. • Standard specifications have been developed (and continue to be developed) for major treatments such as thin-lift AC overlays and full granular aggregate seal coats. They are reasonably successful in producing quality products. • Inspect and test to insure specs are met. • Performance related requirements that we have are pretty simple and simply require the product to perform to a cer- tain level for 1 or 2 years. For example, for sealcoat, if there is a lack of aggregate coverage, the contractor is required to come back and correct the deficiency. Overall we get good performance but when not there can be disputes as to whether it is a workmanship issue or whether our snowplows were too rough on the seal (for example). • Some HMA mill and overlay and overlay projects have smoothness specifications and joint density specifications. • Most of our preventive maintenance treatments do not have performance related specifications. An exception to this is with diamond grind projects. Each project is tested for rideability prior to grinding, a simulation is performed to deter- mine the expected IRI after grinding, and thresholds are set accordingly. • They have made the contractor pay attention to details. Question 20 If you indicated that you do not have performance-related specifications, what are your plans for implementing them? • None at present. • Uncertain. • Possibly in the future for seal coat, fog seal, and rejuvenators. • We have written performance based specs for crack sealing/crack filling, but they have not been used to date. • I would like to review other states’ warranties and see if it is something we can implement. • We have no plans to implement performance-based specifications at present. • No plans at this time. • It is our desire to develop performance-related specifications as we gain more knowledge of the performance indicators and parameters. • At this time, we will most continue to use QA/QC specifications. • None. • See previous question for my answer pertaining to QA/QC. • Don’t know. • No current plans for implementation. Following national trends for future consideration. • None at this time. • Our specifications engineer is recommending moving to performance related specifications in the next major revision of our specification book. • FLH has a study under way looking at the feasibility of using performance-related specifications for polymer-modified asphalt emulsions for chip seals, slurry seals, and microsurfacing. 166

167 • As new methods to measure performance that are not subjective become available MN/DOT will evaluate them and implement them. Question 21 For RURAL high-traffic-volume roadways, which treatments do you use to address the following pavement performance issues. Please check all that apply. Tables C.23 and C.24 present the agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included.

168 Table C.23. Summary of Preventive Maintenance Treatments Used to Address RURAL HMA Pavement Performance Issues Percent Responses HMA-Surfaced Pavement Treatments Light Moderate Heavy for RURAL High-Traffic-Volume Smoothness/ Surface Surface Surface Number of Roadways Raveling Oxidation Bleeding Ride Quality Friction Noise Distress Distress Distress Responses Crack fill 0 0 0 10 0 0 74 61 19 31 Crack seal 3 3 3 5 3 0 84 65 19 37 Cape seal 100 100 33 33 33 0 100 100 0 3 Fog seal 67 83 0 0 0 0 22 6 0 18 Scrub seal 67 67 0 0 0 0 67 33 0 3 Slurry seal 65 82 0 24 24 0 59 18 0 17 Rejuvenators 38 75 12 0 0 0 12 12 0 8 Single-course microsurfacing 57 71 29 31 57 11 77 37 6 35 Multiple-course microsurfacing 53 70 30 37 53 13 67 70 17 30 Single-course chip seal 42 70 24 9 52 0 79 42 3 33 Multiple-course chip seal 45 59 18 14 45 0 59 68 9 22 Chip seals with polymer-modified 42 65 15 8 58 0 77 50 8 26 asphalt binder Ultra-thin bonded wearing course 50 71 29 46 83 25 88 50 8 24 (e.g., NovaChip) Thin HMA overlay (<40 mm [<1.5 in.]) 66 59 41 76 44 29 85 71 20 41 Cold milling and HMA overlay 68 55 43 82 39 20 73 80 41 44 (<40 mm [<1.5 in.]) Ultra-thin HMA overlay 53 63 37 63 58 21 84 47 11 19 (<20 mm [<0.75 in.]) Hot in-place HMA recycling 50 38 25 62 38 12 62 62 38 16 (<50 mm [<1.95 in.]) Cold-in-place recycling 24 29 19 43 19 10 43 71 67 21 (<100 mm [<4.0 in.]) Profile milling (diamond grinding) 0 0 6 94 62 6 38 19 0 16 Ultra-thin whitetopping 20 13 13 60 20 7 40 60 60 15 Drainage preservation 0 0 0 17 0 0 33 83 83 6 Other (see below) 50 0 100 50 50 0 0 50 50 2 Other Treatments (Table C.23): • 1.5 in. HMA mill and fill. • Crack fill and crack seal. Prevent water intrusion; ultra-thin whitetopping (major rehabilitation). • Shot blast or water blast.

Table C.24. Summary of Preventive Maintenance Treatments Used to Address RURAL PCC Pavement Performance Issues Percent Responses PCC-Surfaced Pavement Treatments Light Moderate Heavy for RURAL High-Traffic-Volume Smoothness/ Surface Surface Surface No. of Roadways Raveling Oxidation Bleeding Ride Quality Friction Noise Distress Distress Distress Responses Concrete joint resealing 5 0 0 27 0 14 91 36 9 22 Concrete crack sealing 0 0 0 14 0 11 96 46 4 28 Diamond grinding 3 0 0 82 58 37 24 32 5 38 Diamond grooving 0 0 0 56 94 25 12 12 6 16 Partial-depth concrete pavement patching 3 0 0 35 0 6 53 79 38 34 Full-depth concrete pavement patching 0 0 0 34 2 5 22 73 80 41 Dowel bar retrofit (load-transfer restoration) 0 0 0 55 3 6 24 42 36 33 Thin PCC overlays 0 0 0 45 18 9 36 64 64 11 Ultra-thin bonded wearing course 8 0 0 69 54 15 23 23 0 13 (e.g., HMA < 25 mm [1 in.]) Thin HMA overlay (<40 mm [<1.5 in.]) 5 5 5 58 37 26 37 42 11 19 Drainage preservation 0 0 0 0 0 0 50 75 100 4 Other (see below) 0 0 0 0 0 0 0 0 0 0 169 Other Treatments (Table C.24): • Crack fill, crack seal, and drainage preservation. Prevent water intrusion; thin PCC overlays (major rehabilitation).

Question 22 For URBAN high-traffic-volume roadways, which treatments do you use to address the following pavement performance issues. Please check all that apply. Tables C.25 and C.26 present the agency responses and include summary statistics associated with the answers. Indi- vidual agency comments associated with this question are also included. Question 23 Does your agency consider user costs in the treatment selection process for preventive maintenance applications? (Check the one answer that is most representative.) Based on 56 responses, the following percentages of “Yes” and “No” were observed: • Yes: 21% • No: 79% Question 23 (continued) If “Yes,” are user costs quantified numerically in your treatment selection process? Based on 13 responses, the following percentages of “Yes” and “No” were observed: • Yes: 38% • No: 62% If “No,” does your agency have plans to begin considering [or incorporating] user costs in the treatment selection process? Based on 52 responses, the following percentages of “Yes” and “No” were observed: • Yes: 23% • No: 77% Individual comments included: • Not specifically, but we are starting to use FHWA’s RealCost software, which can incorporate user costs. • We have attending classes detailing the processes. • To evaluate cost-effectiveness of treatments. • Actually, our plans are to indirectly incorporate user costs through the development and implementation of more com- prehensive performance requirements. • It is currently included, whether it be formally or informally. • We will not spend limited funds on low-volume roads. We track ADT and spend the funds we have on the routes that tend to get the most traffic. • We are considering the development of life-cycle costs, including user costs, for preservation projects in order to pro- mote the use of alternate bidding. • We already do. • Asset management has been developed and implemented. • Used in the consideration of lane closure times. • I have heard that we are looking into it but have no direct knowledge. 170

171 Other Treatments (Table C.25): • Crack fill and crack seal. Prevent water intrusion; ultra-thin whitetopping (major rehabilitation). • Shot blast or water blast. Table C.25. Summary of Preventive Maintenance Treatments Used to Address URBAN HMA Pavement Performance Issues Percent Responses HMA-Surfaced Pavement Treatments Light Moderate Heavy for URBAN High-Traffic-Volume Smoothness/ Surface Surface Surface Number of Roadways Raveling Oxidation Bleeding Ride Quality Friction Noise Distress Distress Distress Responses Crack fill 0 0 0 6 0 3 81 56 12 32 Crack seal 0 0 0 8 0 5 86 62 16 37 Cape seal 100 100 0 0 0 0 67 67 0 3 Fog seal 56 81 0 0 0 0 19 6 0 16 Scrub seal 60 60 0 0 0 0 60 20 0 5 Slurry seal 67 87 7 7 20 0 80 20 0 15 Rejuvenators 33 83 0 0 0 0 0 17 0 6 Single-course microsurfacing 67 60 27 33 50 7 83 40 0 30 Multiple-course microsurfacing 69 65 35 46 50 8 73 73 15 26 Single-course chip seal 33 53 0 0 67 0 80 47 0 15 Multiple-course chip seal 38 54 0 0 46 0 62 69 15 13 Chip seals with polymer-modified 47 60 7 7 53 0 93 67 13 15 asphalt binder Ultra-thin bonded wearing course 50 64 36 55 73 32 86 41 9 22 (e.g., NovaChip) Thin HMA overlay (<40 mm [<1.5 in.]) 65 57 45 72 40 25 90 65 20 40 Cold milling and HMA overlay 74 53 50 76 37 24 76 79 42 38 (<40 mm [<1.5 in.]) Ultra-thin HMA overlay 62 69 44 62 62 31 94 38 12 16 (<20 mm [<0.75 in.]) Hot in-place HMA recycling 50 42 33 50 42 17 67 50 50 12 (<50 mm [<1.95 in.]) Cold-in-place recycling 20 13 20 40 20 13 47 93 60 15 (<100 mm [<4.0 in.]) Profile milling (diamond grinding) 0 0 6 94 59 12 18 24 0 17 Ultra-thin whitetopping 21 14 14 50 21 14 36 64 43 14 Drainage preservation 0 0 0 0 0 0 25 75 75 4 O ther (see below) 50 0 100 50 0 0 0 50 50 2

172 Table C.26. Summary of Preventive Maintenance Treatments Used to Address URBAN PCC Pavement Performance Issues Percent Responses PCC-Surfaced Pavement Treatments Light Moderate Heavy for URBAN High-Traffic-Volume Smoothness/ Surface Surface Surface Number of Roadways Raveling Oxidation Bleeding Ride Quality Friction Noise Distress Distress Distress Responses Concrete joint resealing 4 0 0 29 0 17 88 46 4 24 Concrete crack sealing 0 0 0 20 0 12 88 52 8 25 Diamond grinding 3 0 0 84 65 41 19 24 5 37 Diamond grooving 0 0 0 56 75 31 19 25 6 16 Partial-depth concrete pavement patching 6 0 0 42 0 3 55 79 36 33 Full-depth concrete pavement patching 2 0 0 42 2 5 35 75 72 40 Dowel bar retrofit (load-transfer restoration) 0 0 0 69 3 7 31 55 41 29 Thin PCC overlays 0 0 0 64 9 0 45 55 36 11 Ultra-thin bonded wearing course 7 0 0 64 57 36 64 50 14 14 (e.g., HMA < 25 mm [1 in.]) Thin HMA overlay (<40 mm [<1.5 in.]) 0 0 0 72 44 33 61 72 11 18 Drainage preservation 0 0 0 0 0 0 25 75 75 4 Other (see below) 0 0 0 0 0 0 0 0 0 0 Other Treatments (Table C.26): • Concrete joint resealing, concrete crack sealing, and drainage preservation—prevent water intrusion; thin PCC overlays (major rehabilitation).

173 Question 24 There are a number of reasons why agencies may not be performing pavement preservation on high-traffic-volume roadways. Please prioritize the additional guidance that you feel is needed for the successful implementation of preservation strategies on high- traffic-volume roadways. Table C.27 presents the agency responses and includes summary statistics associated with the answers. Table C.27. Summary of Additional Guidance Needed for the Successful Implementation of Pavement Preservation Strategies on High-Traffic-Volume Roadways No Guidance Some Guidance Significant Guidance Needed Needed Needed Number of % % % Respondents Other agency experience with treatment 17 61 22 54 Experienced contractor availability list 34 45 21 53 Availability of suitable materials 38 45 17 53 Typical traffic control requirements 57 40 4 53 Typical closure time information 52 42 6 52 Durability/expected treatment life 11 33 56 54 Typical noise associated with treatment 45 47 8 53 Treatment production rates 34 38 8 53 Time needed before trafficking 31 48 21 52 Typical treatment costs by region 19 57 25 53 Applicable traffic volumes 24 35 41 54 Appropriate climatic regions for treatments 25 36 40 53

Next: Appendix D - Other Pavement Preservation Treatments »
Preservation Approaches for High-Traffic-Volume Roadways Get This Book
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TRB’s second Strategic Highway Research Program (SHRP 2) Report S2-R26-RR-1: Preservation Approaches for High-Traffic-Volume Roadways documents the state of the practice of preservation treatment on asphalt and concrete pavements. The report focuses on treatments suitable for application on high-traffic-volume roadways but also discusses current practices for low-volume roadways.

The same project that produced SHRP 2 Report S2-R26-RR-1 also produced SHRP 2 Report S2-R26-RR-2: Guidelines for the Preservation of High-Traffic-Volume Roadways. The report provides suggested guidelines for the application of preservation treatments on high-traffic-volume roadways and considers traffic volume, pavement condition, work-zone requirements, environmental conditions, and expected performance.

An e-book version of this report is available for purchase at Google, iTunes, and Amazon.

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