Evaluating the effectiveness and roadside noise of alternative transverse rumble strip designs

This study conducted field measurements to evaluate the performance of five promising traditional and alternative transverse rumble strip designs in generating effective in-vehicle noise level increases to alert distracted and drowsy drivers while reducing roadside noise levels. The five transverse rumble strip designs consisted of one baseline traditional design and four promising designs including shorter panel, angled, staggered, and sinusoidal designs. The in-vehicle and external noise measurements were conducted following the SAE J1477 standard and the AASHTO Statistical Isolated Pass-by (SIP) method, respectively. The noise measurements were collected using thirteen different vehicles with variations in type, make, size, weight, engine, and model including gasoline, hybrid, and electric sedans as well as SUVs, minivan, pick-up, box, and heavy semi-trailer trucks to represent all vehicles on U.S. roads. The findings of this study confirmed that all five transverse rumble strip designs generated average in-vehicle noise level increases between 3 and 15 dBA that fulfill the NCHRP recommendations for alerting distracted drivers. The analysis results also indicated that the four promising transverse rumble strip designs reduced roadside noise levels by a range of 18% (1.8 dBA) to 77% (7.7 dBA) compared to the baseline traditional design. These research findings provide state Departments of Transportation (DOTs) with new effective designs that maintain the roadway safety benefits of transverse rumble strips while decreasing their roadside noise levels and related complaints from nearby residents.