Logged in as: Public User

Barrier height on outside of superelevation

Question
State WI
Description Text

Wisconsin
superelevates the high side shoulders (first chart).  Is there an issue
with barrier height when a shoulder breaks away from the superelevation (second
chart)?



Keywords
  • Guardrail
Other Keywords none
Date April 8, 2013
Attachment super_1.jpg
Attachment super_2.jpg


Response
Response

Yes, there could be containment issues with barriers placed off a shoulder for the second situation you illustrated (roadway has positive superelevation and shoulder has negative superelevation).  If the difference in slopes is severe enough, the vehicle could become an airborne projectile as it exits the roadway – similar to the effects of vehicles rolling over the front slope breakpoint of a median ditch in the cable project.  To my knowledge, there have not been any studies to evaluate vehicle trajectories or  barrier placement and containment for these situations.  There is an NCHRP project that is investigating barriers placed on curved, superelevated roadways, but I am not sure if they will be investigating situations with differing roadway and shoulder superelevations.

Date April 8, 2013


Contact Us:
130 Whittier Research Center
2200 Vine Street
Lincoln, NE 68583-0853
(402) 472-0965
Email: mwrsf@unl.edu
Disclaimer:
The information contained on the Midwest Roadside Safety Facility (MwRSF) website is subject to change without prior notice. The University of Nebraska and the MwRSF is not responsible or liable, directly or indirectly, for any damage or loss caused or alleged to be caused by or in connection with the use or misuse of or reliance upon any such content, goods, or services available on this site.