1. SAFETY CONSIDERATIONS HOV FACILITIES AND MANAGED LANES IN HOUSTON Suhag Kansara Ned Levine, PhD Houston-Galveston Area Council TRB Conference on HOV and Managed Lanes Houston, TX April 18, 2005

2. Purpose Document crashes on HOV lanes Compare safety of HOV lanes with General Purpose freeway lanes Identify characteristics of HOV crashes

3. Data sources METRO HOV crash data 2001-2004 DPS freeway crash data 1999-2001

4. HOV Corridors in Houston Region

5. HOV Crashes 2001-2004

6. Crashes by time of day: 2001

7. HOV Crashes 2001

8. Crashes on HOV segments

9. Crashes on Freeway segments

10. Crash risk: HOV vs. Freeway lanes

11. Multiple Crash Locations

12. Multiple Crash Locations – large scale

13. Hot-spot locations HOV lanes merging to freeway lanes

14. Direct access ramps merging with HOV lanes from park and ride lots Hot-spot locations

15. Junction related HOV crashes

16. Design compromises in geometrical structure of HOV lane – shoulder width Hot-spot locations

17. Contributing factors Single vehicle crashes HOV facility30% Freeway facility24% Speeding HOV facility53% Freeway facility56% Following too close HOV facility5% Freeway facility3%

18. HOV lanes are safe Design compromises can increase crash risk Trade-off safety between barrier facilities vs. diamond lanes Tentative conclusions

19. Compare barrier facilities with diamond lanes Who is involved in the crashes –Disproportionate number of males –Disproportionate number of persons in their 30s and 40s Do certain groups have more difficulty with barrier facility? Future research

20. For more information, see: http://www.h-gac.com/safety

21. Thank You