Speed cushions are asphalt mounds placed on roadways for the purpose of slowing traffic. Speed cushions are very similar to speed humps, but are designed to allow unrestricted emergency fire access. The City of Phoenix only allows speed cushions on public streets classified as minor collector streets.
Why are speed cushions desirable?
Speed cushions can help control speeding on neighborhood streets, by reducing average speeds. Unlike traditional police enforcement, speed cushions provide continuous service. They may also help discourage cut-through traffic by diverting it elsewhere without slowing emergency fire response times.
Are there any drawbacks to speed cushions?
Yes. Some of the disadvantages include:
- Residents living near speed cushions may experience increased noise levels as vehicles traverse speed cushions day and night.
- Although it’s rare, vehicles may drive on sidewalks or through front yards to avoid speed cushions.
- Traffic may be diverted to previously quiet parallel streets in the neighborhood.
- Speed cushions may block the flow of drainage water on some streets and can cause flooding problems.
- Speed cushions interfere with street repaving, decreasing the effectiveness of both the speed cushion and the new pavement surface.
- Speed cushions require signing and striping, which some residents consider unattractive.
- On street parking may be prohibited in certain locations.
- Motorized street sweeping equipment cannot be used at speed cushion locations.
Is petitioning required?
Yes. Petitions help show whether strong resident support for speed cushions exists. The City will designate a petition boundary area which usually consists of homes along the street where speed cushions are proposed. Residents must obtain support from at least 70 percent of residents in the petition boundary area, and from every resident whose home is within 100 feet of a proposed speed cushion.
Where can speed cushions be installed?
Speed cushions are permitted on minor collector streets in residential areas where average daily traffic (ADT) is below 10,000 vehicles per day and where the speed limit is at or below 30 mph.
Speed cushions are not permitted:
- Within 200 feet of a STOP sign, YIELD sign or traffic signal.
- Closer than 500 feet apart.
- On or near steep grades or sharp curves.
- At locations that the City of Phoenix Fire or Street Transportation Departments deem unsuitable for speed cushions.
Who pays for speed cushions, and how much do they cost?
Each speed cushion, with required signing and striping, costs approximately $5,500 to install. Depending on a street’s documented average speed, residents pay a portion of the cost, as shown in the table. Residents can collect and pay their portion of the cost of speed cushions any way they prefer.
How can our neighborhood begin the process of installing speed cushions?
The first step in the process is residents talking with their neighbors to engage neighborhood support for possible installation of speed cushions. The second step would be a traffic study, which will show the average speed of vehicles using a street. To request a study, residents should complete and return the attached Speed Cushion Study Request form and obtain signatures representing ten households on the street. A separate form should be completed for each street where cushions are to be considered. Signing this form does not commit residents to support speed cushions, nor does it commit them to provide funding in the future.
Speed Cushion Study Request
Speed Cushion Specifications
Speed Cushion Process
- Residents should speak with their neighbors to gage neighborhood support for a possible traffic calming installation.
- Residents complete and return a Speed Cushion Study Request form (PDF) with signatures representing ten households on the street where cushion are proposed. (Each additional street requires an additional form.)
- City staff conducts a preliminary inspection of the street to determine if speed cushions are appropriate. If not, staff notifies residents in writing that their street is not eligible for speed cushions.
- If the street is eligible for speed cushions, staff conducts a traffic study to document the speed of traffic.
- Residents are notified about the results of the study and the corresponding speed cushion fee.
- If residents wish to pursue speed cushions, they notify city staff. Residents and staff work together to determine appropriate locations for speed cushions, and staff prepares a verbal map showing the proposed locations. Staff may perform a drainage review as needed to assess the potential for flooding.
- Residents speak with their neighbors to gain support for possible placement of speed cushion.
- City staff will prepare a petition and provide it to the residents to circulate. Residents must document at least 70 percent support from the affected area and 100 percent support from residences within 100 feet of any proposed speed cushion.
- Residents submit signed petitions back to the city along with the appropriate speed cushion fee.
- City staff verifies the petitions.
- If consensus building is adequate, staff notifies its contractor to install the cushions as shown on the petitions. After installation, staff will sign and stripe the cushions according to city standards.
To Change Speed Cushion Location
- If, during petitioning, residents wish to change the location of one or more speed cushions, or add speed cushions to the proposal, they must notify city staff. Staff will prepare new petitions showing the new proposal, and residents must discard all previous petitions, signed or unsigned.
- Residents may circulate petitions and obtain signatures for up to 6 months from the distribution of the petitions. Any petitions older than 6 months that are submitted to the city will be rejected.
To Remove An Installed Speed Cushion
- If, at a future time, residents want to remove one or more installed speed cushions, they must submit a petition with at least 51% approval of the original affected area. If approved, residents must pay to remove the cushions.
For questions or comments about the Speed Cushion Program, please call the Street Transportation Department Traffic Services Division at 602-495-5463 .
