Local roads are designed for low speeds and traffic volumes, but motorists increasingly travel on them at higher speeds and in increased numbers. Drivers are aided by technology apps that offer to save time and avoid traffic jams but can also inadvertently create dangerous conditions around elementary schools and in residential communities.
Traffic calming measures are one solution, but they hinder the movement of emergency response vehicles. Most types of traffic calming devices slow a fire department's response to an emergency by approximately 3–10 seconds when every second is critical to the outcome.
A speed bump can be common on roads, but a speed cushion is another option. A speed cushion has spaces or cutouts designed to allow emergency vehicles and buses to pass over it without slowing down.
California’s City of Moreno Valley transportation engineering division, in collaboration with the city's fire department, developed an innovative traffic control device to reduce speeding without impacting emergency vehicles’ response time. Known as a modified speed cushion, the device allows for a wider dual-tire footprint between the center and adjacent cushions to accommodate emergency response vehicles, including large fire engines. Now, such vehicles can navigate the cushion without tossing the fire department’s equipment around and slowing its response time.
Prior to installing the modified speed cushion, the city created a prototype and invited the fire department to test it with its fleet. Following a successful test that was approved by fire officials, two modified speed cushions were installed on a residential street reported to have excessive speeding.
A center-line diverter stripe was installed to keep standard vehicles from driving over the center cushion. Adjacent to the cushions along the curb, red paint was added to prevent vehicle parking. The center cushion was painted yellow with reflective beads illuminating the configuration at night for oncoming traffic. Contractors installed the speed cushion while city staff painted and installed the signs. The unit cost, including parts and labor for a speed cushion built from asphalt concrete, was $5,000. Other materials such as striping, signs, raised pavement markings, and red paint, along with the city staff’s labor, cost about $5,000.
The speed cushion was monitored by transportation engineering staff through a portable camera. A before-and-after speed survey was also conducted, which showed a reduction in speed without a reduction in fire or emergency service response times.
Video monitoring has also shown roadway operations have not been impacted by services from trash, street sweeping, and mail delivery. Residential parking remains ample, with very few residential complaints.
The success of this design has so far met the city's goal to reduce speeding and cut-through traffic without slowing emergency services response.
The project won the Innovative Project Award in the 2024 Build a Better Mousetrap national program.