1. Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009 AFB80 Session 404 January 12, 2009 Contractor Best Practices Transportation Research Board 1

2. H. B. Rowe & Co., Inc. Founded in 1946 Founded in 1946 Heavy Highway / Site Development Heavy Highway / Site Development Licensed in North Carolina, South Carolina, and Virginia Licensed in North Carolina, South Carolina, and Virginia Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 2

3. Slope Stakes Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 3

4. Grade Stakes (Blue Tops) Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 4

5. Natural Ground Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 5

6. 2-D Rough Grading Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 6

7. 2-D Rough Grading Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 7

8. 3D Rough Grading Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 8

9. Bubba’s Rule of Precision Measure it with a micrometer Measure it with a micrometer Mark it with chalk Mark it with chalk Cut it with an axe Cut it with an axe Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 9

10. 2D Operator View Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 10

11. 2-D Manual Grading Manual control of machine Manual control of machine Quality – skill of operator and checker Quality – skill of operator and checker Grade along profile between stations? Grade along profile between stations? Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 11

12. Manual Best Practices Guard stakes adjacent to grade hubs Guard stakes adjacent to grade hubs Notch or Nail grade and correction Notch or Nail grade and correction Visually mark super-elevation changes Visually mark super-elevation changes Stay one station ahead of grader Stay one station ahead of grader Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 12

13. String Sag Can easily “check” out of tolerance Can easily “check” out of tolerance Lower and inconsistent string pull Lower and inconsistent string pull Length on multi-lane can exceed 70 ft Length on multi-lane can exceed 70 ft SAG 0.19 ft - Pull 20 lb, String 0.1oz/ft SAG 0.19 ft - Pull 20 lb, String 0.1oz/ft Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009 crown Maximum SAG Session 404 - Page 13

14. Quality Assurance Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 14

15. 2.5D Sonic Grading Partial vertical automation Partial vertical automation Changes in super-elevation - manual Changes in super-elevation - manual Grade along profile maintained Grade along profile maintained Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 15

16. Sonic Best Practices Steel pins set at Grade Hubs, add 1 ft Steel pins set at Grade Hubs, add 1 ft String runs 1,000 feet or less String runs 1,000 feet or less Visually indicate super changes Visually indicate super changes Complete first pass on string Complete first pass on string Calibrate – Cutting edge & tire change Calibrate – Cutting edge & tire change Paint crown and shoulder breaks Paint crown and shoulder breaks Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 16

17. Quality Assurance Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 17 What happens between stations?

18. Surveying Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 18 “thought I was wrong once but I was mistaken”

19. 3D vs Grade Stakes Assume a interstate project 8.3 km Assume a interstate project 8.3 km Grade Stakes every 20 m (4 per station) VS Control Stakes every 320 m Grade Stakes every 20 m (4 per station) VS Control Stakes every 320 m 1660 Grade Stakes VS 26 Control Stakes Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 19

20. 3D Model Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 20

21. 3D Operator View Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 21

22. 3D Plan View Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 22

23. 3D Cross Section View Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 23

24. 3D Best Practices Control - Standard Control - Standard Control – Use it Control – Use it Control - Maintain Control - Maintain Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 24

25. 3D GPS Grading Fully automated vertical control Fully automated vertical control Cross slope changes automated Cross slope changes automated Grade “anywhere” Grade “anywhere” Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 25

26. GPS Best Practices Fixed base station location Fixed base station location Site Calibration - CONTROL Site Calibration - CONTROL Check consistency daily Check consistency daily Awareness of paper plans Awareness of paper plans Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 26

27. Quality Assurance Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 27

28. 3D Robotic Grading Highly accurate, robotic location Highly accurate, robotic location Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 28

29. Robotic Best Practices Grade Control every 1,000 ft Grade Control every 1,000 ft Establish error limits for set-up Establish error limits for set-up Always measure/update blade wear Always measure/update blade wear Don’t pretend to be a surveyor Don’t pretend to be a surveyor Level the mast when benching Level the mast when benching Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 29

30. Quality Assurance Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 30 Need a more advanced string!

31. Bubba’s Rule Reversed Cut it with a laser Cut it with a laser Mark it with your thumb Mark it with your thumb Measure it with a string Forget about sag, just cut out the crown… Measure it with a string Forget about sag, just cut out the crown… Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 31

32. Conclusion Technology enables quality and speed Technology enables quality and speed Best Practices key to higher quality Best Practices key to higher quality Quality Assurance slow to adopt Quality Assurance slow to adopt Contractor Best Practices – H. B. Rowe & Co., Inc. Jan 2009Session 404 - Page 32