Design and Evaluation of Minnesota's Timber Rub-Rail for Noise Barriers
Karla Lechtenberg, John Rohde, Ronald Faller, James Holloway, Dean Sicking
The Minnesota Department of Transportation's (Mn/DOT's) glue-laminated timber rub rail for noise barriers was developed for situations where a noise barrier will be located within the clear zone and when other types of protection are not considered desirable. The rub rail is intended to prevent an errant vehicle from snagging on the support posts of the noise barrier or on any portions of the noise wall itself. The test installation consisted of 24.86-m (81-ft) of timber rail sections supported by eleven concrete posts. One full-scale crash test, a 1,989-kg (4,386-lb) pickup truck impacting at a speed of 99.4 km/h (61.8 mph) and at an angle of 25.3 degrees, was conducted and reported in accordance with the requirements specified in the National Cooperative Highway Research Program (NCHRP) Report No. 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. The safety performance of the timber rub rail was determined to be acceptable to the TL-3 evaluation criteria specified in NCHRP Report No. 350.
Highway Safety, Noise Barrier, Sound Wall, Timber Rail, Rub Rail, Roadside Appurtenances, Crash Test, Compliance Test