Phase II Development of a Non-Proprietary, Four-Cable, High Tension Median Barrier
Jennifer Schmidt, Dean Sicking, Ronald Faller, Karla Lechtenberg, Bob Bielenberg, John Reid, Scott Rosenbaugh
During the last decade, the use of cable median barriers has risen dramatically. Cable barriers are often utilized in depressed medians with widths ranging from 30 to 50 ft (9.1 to 15.2 m) and with fill slopes as steep as 4H:1V. A careful review of accident records has indicated that passenger vehicles do occasionally penetrate through the standard 3-cable median barrier and enter opposing traffic lanes. As a result, the Midwest States Pooled Fund Program sponsored a research and development project to improve the safety performance of existing, non-proprietary, cable median barriers. These safety improvements included increased cable spacing, increased cable height, the use of four cables, increased cable tension, and optimized cable attachment to posts. Two Test Level 3 crash tests were performed on a four-cable, high-tension median barrier placed in a 46-ft (14.0-m) wide, 4H:1V Vditch. All tests were conducted according to the safety performance guidelines provided in the Manual for Assessing Safety Hardware (MASH). The first test utilized an 1100C small car impacting the barrier located 27 ft (8.2 m) laterally away from the front slope break point. The vehicle was contained and redirected by the barrier and deemed acceptable according to the MASH guidelines. The second test utilized a 2270P pickup truck impacting the barrier placed on a downslope and 12 ft (3.7 m) laterally away from the front slope break point. The pickup truck overrode the system and subsequently rolled, thus the second crash test was deemed unacceptable according to the MASH guidelines.
Highway Safety, Crash Test, Roadside Appurtenances, Compliance Test, MASH, Longitudinal Barrier, Cable Guardrail, High Tension, Median Slope, V-Ditch, 4:1 Median Ditch