Report Result

Back to Search

Performance Evaluation of NDOR Mountable Curbs




Jim Holloway, Dean Sicking, Barry Rosson




Three commonly used Nebraska Department of Roads (NDOR) mountable curbs were investigated for relative safety through a combination of full-scale testing and computer simulation using the Highway-Vehicle-Object-Simulation-Model (HVOSM). The curbs that were investigated included one 4-in. and two 6-in. mountable curbs. The applicability of the model was evaluated with 23 full-scale tests, including thirteen tests on a 4-in. wedge shaped curb, two tests on a 6-in. wedge shaped curb and eight tests on a 6-in. Type I Mountable curb. The crash tests were conducted with 1800 and 4500-lb test vehicles at impact speeds of 45, 50, and 55 mph and impact angles of 5, 12.5, and 20 degrees. HVOSM was first validated against all 23 full-scale crash tests and then used to predict vehicle behaviors at alternate impact conditions. The simulation and crash test program have shown that Nebraska's mountable curbs do not have a potential for causing loss of vehicle control or vehicle destabilization when impacted in a tracking condition. Although the 6-in. mountable curbs were found to cause slightly higher vehicle motions, the differences do not appear significant enough to indicate a reduced safety performance for these curbs. Also, it was determined that the performance of W-beam guardrail can be adversely effected when used in conjunction with roadside curbs. Additionally, through a limited simulation effort of non-tracking impacts, it was determined that these curb types may be traversable over a wide range of vehicle orientations and may not be a significant cause of vehicle rollovers.


Highway Safety, Roadside Safety, Curb, Computer Simulation, Crash test, Compliance test

Other files to download