Development of a TL-5 Vertical Faced Concrete Median Barrier Incorporating Head Ejection Criteria
Scott Rosenbaugh, Dean Sicking, Ronald Faller
A concrete median barrier was designed as a cost efficient alternative to current barriers for use on roadways with heavy tractor-trailer traffic. The barrier geometry was configured to optimize small car and pickup truck safety. After reviewing over 100 previously conducted crash tests, it was determined that vertical faced barriers reduced the risk of vehicle rollover during impacts by eliminating tire climb and vehicle roll. Also, multiple crash test videos were utilized to create a head ejection envelope encompassing the extent of an occupant's head as it is ejected through the vehicle side window during impact. The top of the barrier was cut back to comply with this envelope. The internal steel reinforcement was optimized such that material costs were minimized while providing adequate strength. Slight alterations were made to ensure compatibility with common construction practices, such as slipforming. These alterations resulted from discussions with multiple contractors and members of various State Departments of Transportation. A 200 ft section of barrier was constructed and crash tested with an 80,000-lb tractor trailer in compliance with the NCHRP Report 350 requirements. The barrier performance satisfied all criteria under TL-5 impact conditions.
Highway Safety, TL-5, Concrete Median Barriers, Crash Testing, Tractor Trailer, Head Ejection