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From page 19... ... 19 Managing a 3R Program to Reduce Crash Frequency and Severity Resurfacing, restoration, and rehabilitation programs are managed by highway agencies as part of their effort to preserve and extend the service life of pavements. However, 3R projects also provide an opportunity to consider the need for design improvements to reduce crash frequency and severity. Read the entire page →
From page 20... ... 20 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects • Encouraging improvement of emergency medical services to assist crash victims in receiving on-site and in-hospital treatment as soon as practical after a crash occurs. Read the entire page →
From page 21... ... Managing a 3R Program to Reduce Crash Frequency and Severity 21 ( ) = − × =crash reduction factor 1.00 0.80 100 20% (1) Read the entire page →
From page 22... ... 22 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects not be relied upon unless no better information is available. Read the entire page →
From page 23... ... Managing a 3R Program to Reduce Crash Frequency and Severity 23 Clearinghouse (13) Read the entire page →
From page 24... ... 24 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects Lane Width (ft) Read the entire page →
From page 25... ... Managing a 3R Program to Reduce Crash Frequency and Severity 25 sideswipe, and same-direction sideswipe crashes) , such as the CMFs for lane width shown in Table 3, and pra is the proportion of total crashes constituted by crash types related to lane and shoulder width. Read the entire page →
From page 26... ... 26 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects It is noted in Table 5 that CMFs for composite shoulders are based on the assumption that 50% of the surface width of a composite shoulder is paved and 50% is unpaved (turf) Read the entire page →
From page 27... ... Managing a 3R Program to Reduce Crash Frequency and Severity 27 widths. This approach is an extension of the HSM logic, which does not appear in the HSM but is conceptually consistent with the approach used to determine the composite shoulder CMFs in Table 5. Read the entire page →
From page 28... ... 28 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects 4.3.1.3 Realignment of Horizontal Curves HSM Chapter 10 presents the following CMF for radius and length of horizontal curves on rural two-lane roads (2) Read the entire page →
From page 29... ... Managing a 3R Program to Reduce Crash Frequency and Severity 29 presents CMFs for striping and delineation improvement packages that include replacement of conventional painted markings with more durable markings that often have higher retroreflectivity, including wider edgelines (21) Read the entire page →
From page 30... ... 30 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects 4.3.2 Rural Multilane Undivided Highways 4.3.2.1 Lane Width The CMF for lane widths on multilane undivided roadways is determined with the equations in Table 9 (2) Read the entire page →
From page 31... ... Managing a 3R Program to Reduce Crash Frequency and Severity 31 4.3.2.3 Realignment of Horizontal Curves No CMFs for horizontal curve length, radius, or superelevation on rural multilane undivided highways are presented in HSM Chapter 11, and there is no definitive research on this topic. 4.3.2.4 Superelevation Restoration/Improvement on Horizontal Curves No CMFs are available for superelevation variance or superelevation restoration for horizontal curves that apply specifically to rural multilane undivided highways. Read the entire page →
From page 32... ... 32 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects were reduced by 29.8% on rural multilane undivided highways that were improved with striping and delineation packages. Read the entire page →
From page 33... ... Managing a 3R Program to Reduce Crash Frequency and Severity 33 4.3.3 Rural Multilane Divided Highways (Nonfreeways) 4.3.3.1 Lane Width The CMF for multilane divided roadways is determined with the equations in Table 13 (2) Read the entire page →
From page 34... ... 34 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects Equation 3 can be used to convert these crash-type-specific CMFs to a CMF for total crashes. Read the entire page →
From page 35... ... Managing a 3R Program to Reduce Crash Frequency and Severity 35 4.3.3.8 Guardrail Installation/Restoration Resurfacing, restoration, and rehabilitation projects frequently install new guardrail where it is found to be needed or restore existing guardrail by providing needed maintenance or replacing older guardrail with current designs. There are no formal CMFs for guardrail installation or restoration. Read the entire page →
From page 36... ... 36 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects 4.3.4.2 Shoulder Type and Width There are no CMFs for shoulder width on urban and suburban arterials in HSM Chapter 12. Read the entire page →
From page 37... ... Managing a 3R Program to Reduce Crash Frequency and Severity 37 FI single-vehicle crashes and are determined by using the following equations. The CMF is applicable to lane widths in the range of 10.5 to 14 ft. Read the entire page →
From page 38... ... 38 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects There is no CMF for inside shoulder type on freeways. Read the entire page →
From page 39... ... Managing a 3R Program to Reduce Crash Frequency and Severity 39 [ ] Read the entire page →
From page 40... ... 40 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects If a continuous median barrier is adjacent to one of the directions of travel but not centered in the median, Equations 26 and 27 are used to calculate Pib and Wicb. Read the entire page →
From page 41... ... Managing a 3R Program to Reduce Crash Frequency and Severity 41 ∑= 2 (32) ,P L L ob ob i where L = length of segment (mi) Read the entire page →
From page 42... ... 42 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects 4.4 Investing Available 3R Funds for Maximum Reduction of Crash Frequency and Severity Since funds available for highway infrastructure improvements are limited, it is important that those funds, including funds for 3R projects, be invested to accomplish project objectives, including preserving the pavement and extending the pavement service life; improving traffic operations; and, to the extent practical, maximizing the potential reduction in crash frequency and severity. Read the entire page →
From page 43... ... Managing a 3R Program to Reduce Crash Frequency and Severity 43 4.4.1.1 Lane-Widening Strategy: Widen All Lanes to 12 ft This strategy would select for widening the 2,357.41 mi of roadway with existing lane widths of less than 12 ft. The lane width distribution on the roadway system would be changed as shown in Table 26. Read the entire page →
From page 44... ... 44 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects 4.4.1.3 Lane-Widening Strategy: Minimum AADT Levels This strategy would select for widening the 54.88 mi of roadway that meet the minimum AADT criteria presented in Section 5.4. Read the entire page →
From page 45... ... Managing a 3R Program to Reduce Crash Frequency and Severity 45 This improvement program would provide benefits of $7,817,183 at a cost of $5,603,567 -- equivalent to a benefit–cost ratio of 1.40. Every portion of the 35.34 mi of roadway improved in this program was a cost-effective project, and the benefits for the program as a whole exceeded the costs. Read the entire page →

From page 19...

... 19 Managing a 3R Program to Reduce Crash Frequency and Severity Resurfacing, restoration, and rehabilitation programs are managed by highway agencies as part of their effort to preserve and extend the service life of pavements. However, 3R projects also provide an opportunity to consider the need for design improvements to reduce crash frequency and severity.