SPR 800Shoulder or centerline rumble strips (RS) generate noise and vibration to alert drivers when they are departing the lane of travel. Although inexpensive to install, easy to maintain, and very long-lasting, RS are not installed on many roadway segments primarily due to noise concerns of nearby property owners. This study evaluated the feasibility of using sinusoidal RS as a substitute for rounded milled RS on roadway segments in Oregon with lane-departure crash problems. Exterior and interior sound levels and interior vibrations generated by rounded and sinusoidal RS strikes were compared to baseline and no-strike sound levels for 3 vehicle classes (passenger car, van, and heavy vehicle) to establish sound generation and alerts of the 2 designs. A total of 114 vehicle strikes of RS were recorded. Rumble strip strikes by the passenger car and van generated less exterior noise with the sinusoidal than with the rounded design. Interior noise generated by striking the sinusoidal design generated a clearly noticeable alert, suggesting that the sinusoidal rumble strip is still an effective countermeasure. Based on thresholds of human perception for vibration, both rumble strip types generated sufficient vibration to alert the driver. Results for the heavy vehicle were complicated due to bridging of the harrower rounded rumble strip by the tires. The wider cut of the sinusoidal RS generated a clearly detectable increase in exterior roadside noise for the Heavy Vehicle. Likewise, the sinusoidal design created a noticeable interior alert for the HV but the rounded design did not
