Temporary concrete barriers (TCBs) are connected and transitioned to many types of barriers. Unfortunately, little effort has been devoted to this issue. The only transitions previously developed have been between TCBs and safety shaped concrete barriers and TCBs and permanent concrete median barriers. Transitions between TCBs and other common barrier types, such as guardrail, have typically not been full-scale crash tested and may pose a serious hazard to motorists during an impact.
Nebraska Department of Roads (NDOR) has previously funded a project to evaluate the feasibility of designs for a MASH Test Level 3 (TL-3) approach transition between G4(1S) guardrail and free-standing F-shape TCB (M326 â€“ Development of a TL-3 Transition between Temporary Concrete Barrier and Guardrail). While the results of this research are currently being finalized, it appears that the candidate designs have the potential for providing a safe transition between the two barrier systems. However, in order to implement the proposed designs, the proposed transition design must be fully developed and fabricated and then subjected to full-scale crash testing for evaluation to the MASH TL-3 safety requirements. Thus, it is proposed that Phase II of this research project be developed in order to develop the design details and conduct the crash tests required for evaluation of the system.
This research study is directed toward improving the safety by minimizing the risk for the motoring public traveling within our nationâ€™s work-zones and on our highways and roadways. Since W-beam guardrail has proven to provide better safety performance than temporary concrete barriers, the development of an effective transition between the two can help preserve guardrails outside the immediate work-zone area, thus providing an overall higher level of safety for motorists. The new transition would also eliminate the use of an unproven connection between guardrail and temporary barriers. Further, limiting the use of temporary concrete barriers strictly to the work zone area will also minimize the traffic disruption that these barriers can create to motorists passing in work zones.