Logged in as: Public User

Slopes Near End Terminals

Question
State WI
Description Text

Earlier this week I had the opportunity to drive through various construction sites that were retrofitting energy absorbing terminals (See attached pictures).   One question I had was about the slope just off of the gravel widening near the terminal.  In this case the slope is approximately 1.5:1 and the terminal platform is approximately 2' higher than the grass slope.  The grass slope is typically 4:1 or flatter.  Figure 5.1b, of the Roadside Design Guide would indicate that this is acceptable (see page 2).

 

Given the instability of a vehicle during impact with the terminal, should this slope be permitted at the terminal?

Keywords
  • End Treatments & Crash Cushions
Other Keywords none
Date October 19, 2007
Attachment terminal grading question.pdf


Response
Response

The attached figure contains current FHWA guidelines for grading around terminals. The green area must be 3:1 or flatter. Our research would suggest that the orange region could be as steep as 3:1, even though FHWA gives a more conservative recommendation. We do not believe that 1.5:1 is acceptable under any circumstance.

Date October 23, 2007
Attachment Grading near terminals.doc


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.