About the research
The goal of this work was to develop a design for a portable rumble strip given the following criteria: the strip must be deployable without adhesives or fasteners; the strip must stay in place under traffic traveling at highway speeds; the strip must be deployable by two workers; and the strip must be transportable in a standard pickup bed.
Aerodynamic analyses were conducted using a low speed wind tunnel and computational fluid dynamics (CFD) modeling to map the pressures occurring in the wake of a tractor trailer traveling at highway speeds. Vehicle modeling was used to examine the interaction between vehicle tires and a strip. Prototyptes were fabricated and tested.
During testing, vehicle speed was measured with a laser gun, sound in the cabin was measured and recorded using a PC-based system, and the motion of the rumble strip during traversal was recorded using a high-speed video camera. The prototype strips were also outfitted with two accelerometers to measure the motion of the strip. The design was appropriately modified based on the test results and subsequent analyses.
The results support the premise that a strip can be fabricated that will not lift, slide, or tip under traffic. A fourth type of motion was identified during the testing, strip bound, that precipitated a significant in the design, but which could not be more thoroughly studied within the scope of this project. The design was modified to help minimize the effects of bounce, and the final Phase 1 design will be prototyped and tested during Phase 2 of this work.