Quieter Rumble Strip Design Standards
Community & Cultural Concerns, Environmental Process
Research Idea Scope
TERI Database Administrator Notes: Not recommended at present time by 2009 Environmental Process Subcommittee.
Vehicles striking rumble strips can elevate wayside noise levels and generate noise complaints in noise sensitive areas, especially at night on low ADT roadways. Rumble strip noise might be minimized through more thoughtful design that optimizes a pattern to introduce a controlled amount of tactile feedback through the steering wheel rather than generate an excessively loud audible tone that competes with vehicle cabin noise and generates wayside noise. The study would develop an optimal depth and spacing pattern for rumble strips which would communicate tactilely and audibly to the driver and potentially lower overall passby noise levels as the vehicle traverses the rumble strip. The measurement matrix should examine several variables: light vehicles with a standard wheel diameter, and heavy trucks, with a standard wheel diameter, at both high (50+mph) and low (35 mph) speeds. Impact to bicycles and/or a bike friendly design should be considered also as well as patterns under a single side of a vehicle and under both sides of the vehicle. Different chassis and wheel mounting configurations for light vehicles and trucks/SUVs might also be considered for the test matrix. On the inside of the vehicle, a 3-axis accelerometer would quantify steering wheel feedback, and a standard in-vehicle noise measurement system would capture sound at the driver’s ear level. On the exterior, wayside noise levels would be captured by a controlled passby noise measurement which could be used to calculate distant noise level impacts. Test-drivers would be interviewed for their opinion of effectiveness.
Urgency and Payoff
Community noise levels could be lowered in areas where safety is a concern and rumble strips are installed. Traffic-related noise complaints from sensitive areas would decrease. A standardized design plan detail would assist engineers in providing a safety feature and avoid creating a noise nuisance.
Bruce Rymer, CalTrans