Evaluation of low noise transverse rumble strips in proximity to a stop controlled intersection

Abstract

Transverse rumble strips (TRS) can generate noise and vibration to alert drivers when they approach an intersection. The feasibility of using shallower epoxy filled TRS to substitute for traditional TRS to address noise concerns was evaluated. Twenty-four prove vehicle strikes with TRS were recorded and exterior sound generated by TRS strikes were compared to baseline and epoxy filled sound. Experimental framework was based on the AASHTO SIP Method. Humans can detect differences in noise levels at 3 dB(A), with 5 dB(A) being easily noticed. Compared to traditional TRS, the shallower epoxy filled TRS average sound level measurements dropped from 93 dB(A) to 88 dB(A), a noticeable 5 dB(A) difference. When the peek (max value) of both measurements are compared, the difference in sound was 6 dB(A), or a clearly noticeable change. Additionally, the sound generated from the epoxy TRS is higher than the paved condition, where the TRS was completely paved with asphalt, at 95% CI [-1 dB(A), 9 dB(A)]. This CI range indicates that the epoxy filled TRS strike was indiscernible at least, and clearly noticeable at most compared to a baseline, meaning that the epoxy TRS is noticeable compared to background traffic. Comparing the before condition TRS to the after paved TRS, the average sound level measurement dropped from 94 dB(A) to 83 dB(A), a clearly noticeable 11 dB(A) difference. However, the peak difference in sound measurement is approximately 18 dB(A). This indicates the original TRS is nearly four times louder than the same baseline passing vehicle.