Date of this Version
Meyer, D.T., Lechtenberg, K.A., Faller, R.K., Bielenberg, R.W., Rosenbaugh, S.K., Reid, J.D. (2017). "High-Tension Cable Median Barrier for Use in 6H:1V V-Ditch (Test No. MWP-8)" Nebraska Department of Transportation Research Report TRP-03-331-17.
The Midwest States Pooled Fund Program has been developing a prototype design for a non-proprietary, high-tension cable median barrier for use in a 6H:1V V-ditch. This system incorporates four evenly spaced cables, Midwest Weak Posts (MWP) spaced at 8 to 16 ft (2.4-4.9 m) intervals, and a bolted, tabbed bracket to attach three or four cables to the sides of each post. According to the Manual for Assessing Safety Hardware (MASH) testing matrix for cable barriers installed within a 6H:1V median V-ditch, a series of eight full-scale tests are required to evaluate the safety performance of a system. A ninth test is required to establish the working width for the systems with variable post spacing.
Several previous tests have failed due to posts penetrating the occupant compartment. In order to mitigate this behavior, a modified MWP was designed. Test no. MWP-8 was conducted on the modified barrier system, consisting of MWPs with rounded top edges and a ¾-in. (19-mm) diameter weakening hole at the groundline. This test was conducted according to MASH test designation no. 3-10 and utilized an 1100C passenger car impacting the barrier on a level terrain. The vehicle was contained by the system. Through the initial two vehicle crossover events across the barrier and posts, no floorpan tearing was observed. During the third impact series with the posts, post penetration into the occupant compartment and floorpan tearing was observed. Therefore, test no. MWP-8 was deemed unacceptable.