Test Level 4 Evaluation of the Minnesota Combination Bridge Rail

A safety performance evaluation of the Minnesota concrete parapet with brush curb and metal rail (Minnesota Combination Bridge Rail) was conducted for the Minnesota Department of Transportation (Mn/DOT) as part of Year 4 of the Midwest States Regional Pooled Fund Program. The safety performance evaluation of this bridge rail system was conducted and reported according to the criteria specified in Test Level 4 of the National Cooperative Highway Research Program (NCHRP) Report No. 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. This testing involved impacts with an 8000-kg single-unit truck, a 2000-kg pickup truck, and an 820- kg small car. The bridge rail design was modified following the 2000-kg pickup truck test in order to reduce the potential for snagging. After this modification was made, and the system was retested, the safety performance of this system was found to be acceptable and meets the safety standards set forth in Test Level 4 of NCHRP 350