Placement Guidance for Temporary Concrete Barriers in Construction Work Zones: Developed with Roadside Safety Analysis

An important design decision in construction work zones concerns the use and placement of temporary barriers. The temporary concrete safety shaped barrier is the option preferred by most state transportation agencies. No consensus on specific warrants or nationally recognized guidance exists. Of 32 state departments of transportation responding to a recent survey, 24 ranked having or improving work zone guidance on “traffic barriers and roadside design” as “most important/critical.” The objective of this paper is to investigate and evaluate the information, tools, and procedures available to aid individual designers and agencies in developing guidance for the use of traffic barriers in construction work zones. Principles of roadside barrier use for permanent roadways will be covered. Also covered will be benefit-cost analysis and adaptation of permanent roadway procedures and programs, specifically the Roadside Safety Analysis Program (RSAP), for the purpose of developing work zone barrier guidance. Results show that the modeling of specific work zone scenarios and development of generalized barrier placement guidance for practitioners based on cost-effective principles are both feasible. This type of analysis can be done by adapting algorithms in RSAP intended for permanent roadway analysis to construction work zones. General guidelines similar to the median barrier warrants for permanent roadways in the “Roadside Design Guide” were developed for construction work zones. In addition, it was concluded that current encroachment models and crash severity indexes may not be well suited for permanent roadways or construction work zones.