1. Automatic Pavement Cracking Distress Measurement System Bugao Xu and Yaxiong Huang University of Texas at Austin bxu@mail.utexas.edu (512) 471-7226 December 2004

2. Automated Pavement Distress Measurement Vehicle Digital Line Scan Camera

3. System Specifications One linescan camera: 2k pixel, 37k scan/sec One frame grabber: 4 taps, 40MB each GSP: position and speed LED or halogen linear lighting device (patent pending) Imaging Resolution: min 1.786 mm per pixel Image capturing and processing: Real-time Network support

4. System Capabilities Real-time inspection Distance coverage: 100% Lane coverage: Up to 12 feet (3.65 m) Vehicle speed: 3-70 mile/hour (5 to 112 km/hour) Pavement type :flexible and rigid pavements Weather tolerance: cloudy or sunny Night operation: same as in daytime

5. System Output Format: PMIS and ASSHTO protocols Summary data: at a given interval Crack map: continuous Snapshot: at an interval AVI images: saved up to one km Compressed images: continuous

6. System Performance Repeatable over multiple runs: R 2 >0.8, CV 5.0~14% Repeatable over testing speeds Repeatable under different cloud conditions Reproducible (vehicle to vehicle) Output data directly up-loadable input PMIS Measurements correlate well with manual ratings for flexible pavements

7. System Benefits Safety (removing raters for roadway) Low cost compared to visual rating High data Quality Multiple data types with one pass of vehicle Easy data management

8. Continuous Crack Maps (40ft) Unsealed CrackSealed Crack

9. Asphalt Pavement Correlation of Multiple Scans Longitudinal Crack on SL360 R1 432 to 436. R 2 = 0.9519 0 20 40 60 80 100 120 020406080100120 1 st Scan 2 nd Scan

10. Multiple Scans Longitudinal Cracks on SL360 R1 432 to 436 0 50 100 150 200 250 300 151101151201 stations Feet/station #1 #2 #3 Transverse Cracks on SL360 R1 432 to 436 0.0 2.0 4.0 6.0 stations Count/station 151101151201 #1 #2 #3

11. Weather Conditions Longitudinal Crack on SL360 R1 432 to 436 0 50 100 150 200 250 300 151101151201 Stations May 8 (heavily cloudy) May 9 (sunny) May 20 (cloudy) Feet\Station

12. Vehicle Speeds Transverse Cracks on SL360 R1 432 to 436 Count\Station Longitudinal Crack on SL360 R1 432 to 432+0.5 Feet\Station 0 40 80 120 160 200 050010001500200025003000 Scanned Section (ft) 35 mph 45 mph 55 mph 0.0 1.0 2.0 3.0 Scanned Section (ft) 050010001500200025003000

13. Long Distance Data (24 miles) longitudinal crack Miles 0 50 100 150 200 16.017.018.019.020.021.022.023.024.0

14. Concrete Pavement Transverse (Vehicles 1 and 2)

15. Concrete Pavement Transverse Cracks Vehicle V1V2 R1-R20.8840.963 R1-R30.9600.964 R2-R30.9080.966 Scan Correlations of Different Runs (Transverse)

16. Concrete Pavement Transverse Cracks (V1 and V2) R10.970 R20.897 R30.936 Correlations

17. Concrete Pavement AASHTO Left Wheel Path (V1)

18. Concrete Pavement AASHTO RWP (V1)

19. Concrete Pavement AASHTO Between Wheel Path (V1)

20. Concrete Pavement AASHTO Outside Wheel Path (V1)

21. Concrete Pavement AASHTO Correlations (V1) LWPRWPBWPOWP R1-R20.95640.90710.93900.9701 R1-R30.94590.83240.91890.9427 R2-R30.92150.82630.92010.9293

22. Asphalt: Longitudinal Crack(2)

23. Asphalt: Longitudinal Crack (4)

24. Asphalt: Transverse Crack (1)

25. Asphalt: Transverse Crack (2)

26. Asphalt: Alligator Crack (2)

27. Asphalt: Alligator Crack (4)

28. Asphalt: Sealed Crack (2)

29. Asphalt: Sealed Crack (3)

30. Asphalt: Raveled Pavement

31. Asphalt: Patched Pavement

32. Asphalt: Dark Image (1)

33. Asphalt: Dark Image (2)

34. Asphalt: Bright & Fuzzy Image (1)

35. Asphalt: Bright & Fuzzy Image (2)

36. Concrete: No tinning (3)

37. Concrete: No tinning (4)

38. Concrete: No tinning (10)

39. Concrete: No tinning (11)

40. Concrete: Wide tinning (1)

41. Concrete: Wide tinning (2)

42. Concrete: Spalled (1) Spalled crack