Field Evaluation and Predictive Modelling of Low-Noise Sinusoidal Rumble Strips for Indian Rural Highway Corridors under Mixed Traffic

Abstract

Roadway departure warning treatments are increasingly relevant for Indian highway corridors where high-speed motorized traffic, heavy vehicles, roadside settlements, and informal access points often occur within a short distance of one another. Rumble strips can support lane-keeping and shoulder encroachment awareness, but their acoustic effects require careful evaluation before wider adoption near habitations. This study reports a field experiment on a resurfaced rural divided highway corridor in southern India to evaluate whether low-profile sinusoidal rumble strips can reduce roadside noise while retaining adequate in-cabin alerting performance under mixed traffic. Six milled edge-line rumble strip designs were constructed and tested using seven enclosed vehicle categories at three operating speeds. External and in-cabin sound pressure levels were recorded for 864 valid pass-by events under dry pavement and low-wind conditions. A paired acoustic comparison, mixed-effects regression, warning-threshold analysis, and design utility model were used to interpret the data. The conventional rectangular design produced the largest mean roadside noise increment, especially for heavy commercial vehicles at higher speed. Three sinusoidal designs reduced mean roadside noise by 5.8 dBA to 8.1 dBA relative to the conventional design while maintaining median in-cabin increments between 6.9 dBA and 9.4 dBA. The most stable compromise was a tapered sinusoidal design with moderate wavelength and reduced net depth. The findings suggest that low-noise rumble strip geometry can be adapted to Indian highway conditions, provided that installation is guided by speed, vehicle mix, shoulder width, and nearby receptor sensitivity.