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A-1 A P P E N D I X A Examples of Roughness at Built-In Road Features This appendix presents examples of roughness at built-in road features. These examples represent various types of built-in features found on 63 urban and low-speed roadway segments in Philadelphia County, Pennsylvania. For each example, a description, an elevation profile, a roughness profile, and one or more images are presented in this appendix. In some cases, a high-pass filter was applied to the elevation profile so that the features of interest were not obscured by large elevation changes associated with grade changes and long- wavelength effects. In other cases, the long-wavelength content is a component of the feature of interest, and a high-pass filter was not applied. Roughness profiles are provided for the examples with averaging performed over various base lengths. A standard base length of 25 ft (7.62 m) was used in the majority of cases. However, roughness profiles were averaged over a base length of 10 ft (3.05 m) when a high degree of localization was needed to emphasize the effect of the feature; and roughness profiles were averaged over 100 ft (30.5 m) to illustrate cases where the roughness was distributed over a wider area. Railway crossing (PA Route 1014 Eastbound): See Figures A-1 and A-2. This crossing is at an elevation below the surrounding pavement, with a slope break at the trailing edge of the apron. The localized roughness is greatest at the slope break. The railway crossing covers 21 ft (6.4 m) of distance in the profile. Railway crossing (PA Route 2001 Northbound): See Figures A-3 and A-4. This crossing is skewed. The rails are a standard (perpendicular) distance of 56.5 in (143.5 cm) apart. The skew causes them to appear 20 ft (6.1 m) apart in the profile. Deterioration and gaps at the interfaces between the rails and the pavement contribute to the roughness. Railway crossings (PA Route 2001 Northbound): See Figures A-5 and A-6. This profile includes three railway crossings. All three crossings are skewed such that they appear in the left profile first. The first set of rails is surround by asphalt concrete (AC). The second set is surround by AC patching. The third is surround by Portland cement concrete (PCC) patching. The rails contribute to roughness at all three crossings. Slope breaks contribute to roughness at the leading edge of the first and second set of rails, and the third set of rails (and the surrounding PCC) is above the prevailing grade of the surrounding pavement. Railway crossing with swell (PA Route 2001 Northbound): See Figures A-7 and A-8. This crossing is above the prevailing grade of the road, and the profile includes a swell several inches high. The swell causes the roughness to increase over a portion of the area shown, but does not cause a large peak in the short- interval roughness profile. The portions of the apron outside of the rails are below the level of the surrounding pavement, and below the area between the rails. This contributes to the roughness. Road below railway overpass with utility overs (PA Route 4017 Northbound): See Figures A-9 through A-11. The elevation profile includes a wide dip that is lowest beneath the railway overpass. Although the dip is several inches below the surrounding profile, the dip occurs gradually, therefore an increase in the roughness profile is not apparent. The utility cover at 8,291 ft (2,527.1 m) is above the surrounding pavement. The roughness profile shows increased roughness at 7,784 ft (2,372.6 m), which is caused by a utility cover. The profile adjacent to this utility cover contains a dip, which may have been caused by the settlement of the surrounding pavement. (See Figure A-10.) Two utility covers cause the highest peak
A-2 values in the roughness profile where the profiler sensors passed directly over them. Patching surrounds the utility cover at 8,037 ft (2,449.7 m). (See Figure A-11.) Intersection with trolley tracks (PA Route 3008 Eastbound): See Figures A-12 and A-13. The elevation profile includes a swell at the intersection due to the crown of the crossing street. Although the swell does not cause a localized peak in the roughness profile, it causes an increase in roughness over the entire area. Trolley tracks are located within the intersection. Three other features in the elevation profile contribute to roughness at the intersection: 1. Narrow dips appear 5 ft (1.5 m) apart at the trolley rails. 2. The swell in the profile through the intersection includes a low area within the swell to meet the level of the trolley tracks. 3. A bump appears at the location where the profiler sensor tracked over (or near) a utility cover. This intersection has several features that contribute to localized roughness that are close to each other. As a result, the roughness profile shows a high level of roughness throughout the intersection, rather than isolated peak values at each feature. Intersection with trolley tracks and textured pedestrian crossings (PA Route 3007 Northbound): See Figures A-14 and A-15. Several features contribute to roughness through this intersection: 1. The profile rises to meet the elevation of the trolley tracks from slope breaks at the outer edges of textured pedestrian crossings. 2. Narrow dips appear at the trolley rails. 3. Textured pedestrian crossings cause disturbances in the profile, particularly at the edges. The crown in the cross street may also influence the shape and severity of the swell through this intersection. Metal plates (PA Route 3008 Eastbound): See Figures A-16 and A-17. The profiler passed over metal plates covering on-going utility work on this section. The profile includes step changes in elevation at the leading and trailing edge of the area with the metal plates, and at several locations within the covered area. Much higher roughness is registered in this area than the surrounding pavement. The left wheel path is patched for 70 ft (21.3 m) past the end of the metal plates. The roughness profile registers a peak at the end of the patching. Utility covers (PA US Route 13 Northbound): See Figures A-18 and A-19. The profile includes two areas with utility covers. In the first area, the pavement surface has three utility covers to the right of the lane center, and one utility cover in the right wheel path. (See Figure A-19, left.) The right elevation profile includes roughness where the sensor in the profiler passed near the first three utility covers because of their influence on the pavement around them. The profile also includes a dip at the utility cover in the wheel path. In the second area, two utility covers that are located below the elevation of the surrounding pavement cause localized roughness. (See Figure A-19, right.) They are close to each other, and they both contribute to one peak in the roughness profile. Slope breaks for drainage (PA Route 532 Northbound): See Figures A-20 and A-21. The elevation profile includes the grade of the road, which is provided for drainage, and a slope break occurs at the location of a curb drain inlet at the right lane edge. The elevation profile also includes a narrow dip at a utility cover. The slope break and the utility cover contribute to roughness as shown in the roughness profile. Drainage inlets (PA Route 2001 Northbound): See Figures A-22 and A-23. The elevation profile includes narrow dips at two drainage inlets that are located below the elevation of the surrounding pavement. The elevation profiles include very narrow downward spikes at the leading and trailing edge of each drainage inlet. The roughness at both drainage inlets is much higher than the surrounding pavement. Drainage inlets (PA US Route 13 Northbound): See Figures A-24 and A-25. The elevation profile includes narrow dips at 10 water inlets that are located at the right edge of the right lane on a bridge deck. Each drain inlet contributes to the roughness. However, the amount of roughness at each inlet depends on whether the sensor in the profiler passed directly over it.
A-3 Grades for drainage (PA Route 1009 Northbound): See Figures A-26 and A-27. The pavement contains grades that are provided for drainage toward the curb inlets. The elevation profile shows a slope break at the four locations where curb inlets are located at the right lane edge. Each slope break contributes to roughness. Two curb inlets are located on either side of a crowned intersection. A utility cover is also located adjacent to the intersection. The curb inlets, utility cover, and the crown of the intersection all contribute to the roughness in the area of the intersection. The left image in Figure A-27 shows the curb inlet at 6,176 ft (1,882.4 m). The right image in Figure A-27 shows the curb inlet that precedes the intersection. Textured pedestrian crossings at an intersection (PA Route 291 Eastbound): See Figures A-28 and A-29. Several features contribute to roughness through this area: (1) crown of the intersecting roadway, (2) unevenness within each pedestrian crossing, (3) elevation of each pedestrian crossing above the surrounding pavement, and (4) slope breaks and dips at the strips of concrete at the edges of a pedestrian crossing. The roughness in the area of the pedestrian crossing is higher than the pavement before and after it, with the peak roughness occurring at the pedestrian crossings. Textured pedestrian crossings at an intersection (PA Route 291 Eastbound): See Figures A-30 and A-31. Several features contribute to roughness through the area shown: (1) crown of the intersecting roadway, (2) unevenness within each pedestrian crossing, (3) elevation of each pedestrian crossing that is below the surrounding pavement, (4) dips at the strips of concrete at the edges of the pedestrian crossings, and (5) a wide transverse crack in the center of the intersection. Concrete pad for a bus stop (PA Route 2004 Eastbound): See Figures A-32 and A-33. The concrete pad contains five slabs. Roughness occurs at a bump at the transition from AC to PCC at the start of the pad, and at a downward change in elevation in the transition from the end of the pad to a textured pedestrian crossing. Crowned intersection (PA Route 3 Eastbound): See Figures A-34 and A-35. The area shown includes four crowned intersections. The low areas surrounding each intersection may be artifacts of high-pass filtering. No additional filtering was applied to the elevation profiles obtained from the profiler for plotting. Much more roughness occurs at the intersections than in the areas between them. Figure A-35 shows an image from the first intersection at S 62nd Street. Cobblestone surface (PA Route 3008 Eastbound): See Figures A-36 and A-37. The area with a cobblestone surface is much rougher than the area surfaced with AC that follows. Trolley tracks in the lane (PA US Route 13 Northbound): See Figures A-38 through A-42. Figures A-38 and A-40 show profiles over an area of pavement with trolley tracks within the lane. On the left side, the profiler measured a path just to the left of the left trolley track. (See Figure A-38.) Settled patches beside the track cause the narrow dips at 9,876 ft (3,010.2 m) and 9,932 ft (3,027.3 m). (See Figure A-39.) On the right side, the profiler measured a path between the tracks. The step changes in elevation at 9,758 ft (2,974.2 m) and 9,832 ft (2,996.8 m) were caused when the profiler moved to the right and the height sensor passed directly over the right trolley track. (See Figure A-40.) The profiler moved to the right to avoid an on-coming vehicle that approached the road centerline to pass a stopped cab, which was encroaching on the driving lane. Figure A-41 shows a snapshot of the pending conflict. The roughest area in the right wheel path occurs where the pavement between the trolley tracks had severe distress, as shown in Figure A-42. Trolley tracks in the lane (PA US Route 30 Eastbound): See Figures A-43 through A-45. Figures A-43 and A-45 show profiles over an area of pavement with trolley tracks in the measured lane. As shown in Figure A-43, the right wheel path included a utility cover at 10,723 ft (3,268.4 m) that caused localized roughness. Figure A-44 shows an image of the pavement with the utility cover. As shown in Figure A-45, the left wheel path was much rougher than the right wheel path. It is suspected that the profiler height sensors on the left side passed over or near the trolley tracks in the area shown. Peaks in the left roughness profiles were detected at 10,565, 10,770, and 10,889 ft (3,220.2, 3,287.7, and 3,319.0 m).
A-4 The localized roughness at these locations was most likely caused by the height sensors crossing the tracks. No distress or built-in features other than the trolley tracks were found in the images at these locations. Finger Joint, Elevated Highway (I-95 Eastbound): See Figures A-46 through A-48. Figure A-46 shows an elevation profile over a finger joint on an elevated section of I-95. The joint is shown in Figure A-47. The profile at the joint shown is typical for the profile observed at finger joints on this road segment. The profile includes an upward change in elevation across the metal joint, with a narrow dip at the center. As shown in Figure A-48, the roughness is increased at this feature.
A-5 Figure A-1. Profiles, railway crossing, PA Route 1014. Figure A-2. Image, railway crossing, PA Route 1014.
A-6 Figure A-3. Profiles, railway crossing, PA Route 2001. Figure A-4. Image, railway crossing, PA Route 2001.
A-7 Figure A-5. Profiles, three rail crossings, PA Route 2001. Figure A-6. Image, second railway crossing, PA Route 2001.
A-8 Figure A-7. Profiles, railway crossing with swell, PA Route 2001. Figure A-8. Image, railway crossing with swell, PA Route 2001.
A-9 Figure A-9. Profiles, roadway below railway overpass, PA Route 4017. Figure A-10. Image, roadway below railway overpass, PA Route 4017.
A-10 Figure A-11. Image, utility cover with patching, PA Route 4017.
A-11 Figure A-12. Profiles, trolley tracks within intersection, PA Route 3008. Figure A-13. Image, trolley tracks within intersection, PA Route 3008.
A-12 Figure A-14. Profiles, trolley tracks within intersection, PA Route 3007. Figure A-15. Image, trolley tracks within intersection, PA Route 3007.
A-13 Figure A-16. Profiles, metal plates over utility work, PA Route 3008. Figure A-17. Image, metal plates over utility work, PA Route 3008.
A-14 Figure A-18. Profiles, utility covers, PA US Route 13. Figure A-19. Images, utility covers, PA US Route 13.
A-15 Figure A-20. Profiles, slope brake for drainage, PA Route 532. Figure A-21. Image, slope brake for drainage, PA Route 532.
A-16 Figure A-22. Profiles, drain inlet, PA Route 2001. Figure A-23. Image, drain inlet, PA Route 2001.
A-17 Figure A-24. Profiles, drain inlets, PA US Route 13. Figure A-25. Image, drain inlets, PA US Route 13.
A-18 Figure A-26. Profiles, grades for drainage, PA Route 1009. Figure A-27. Images, grades for drainage, PA Route 1009.
A-19 Figure A-28. Profiles, textured pedestrian crossings, PA Route 291. Figure A-29. Image, textured pedestrian crossings, PA Route 291.
A-20 Figure A-30. Profiles, textured pedestrian crossings, PA Route 291. Figure A-31. Image, textured pedestrian crossings, PA Route 291.
A-21 Figure A-32. Profiles, concrete pad for a bus stop, PA Route 2004. Figure A-33. Image, concrete pad for a bus stop, PA Route 2004.
A-22 Figure A-34. Profiles, crowned intersection, PA Route 3. Figure A-35. Image, crowned intersection, PA Route 3.
A-23 Figure A-36. Profiles, cobblestone surface, PA Route 3008. Figure A-37. Image, cobblestone surface, PA Route 3008.
A-24 Figure A-38. Profiles, left wheel path near trolley tracks, PA US Route 13. Figure A-39. Image, patches beside trolley tracks, PA US Route 13.
A-25 Figure A-40. Profiles, right wheel path straddling trolley tracks, PA US Route 13. Figure A-41. Image, pending traffic conflict, PA US Route 13.
A-26 Figure A-42. Image, distress between trolley tracks, PA US Route 13. Figure A-43. Profiles, right wheel path near trolley tracks, PA US Route 30.
A-27 Figure A-44. Image, utility cover beside trolley tracks, PA US Route 30. Figure A-45. Profiles, left wheel path near trolley tracks, PA US Route 30.
A-28 Figure A-46. Elevation profile, finger joint, I-95. Figure A-47. Image, finger joint, I-95. Figure A-48. Roughness profile, finger joint, I-95.
