Speed humps are asphalt mounds placed on roadways for the purpose of slowing traffic. Speed cushions are very similar speed humps, but are designed with to allow unrestricted emergency fire access. The City of Phoenix only allows speed cushions on public streets classified as minor collector as specified on the Street Classification Map.
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. However, 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.
- On streets containing unauthorized gutter ramps in violation of City codes or Arizona Revised Statutes §28-7053.
- 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 $2,800 to install. Depending on a street’s documented average speed, residents pay either the full $2,800 cost or 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 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
1. Once residents express interest in speed cushions, City staff sends a speed cushion information flier to residents.
2. Residents complete and return a Speed Cushions Study Request form with signatures representing ten households on the street where cushions are proposed. (Each additional street requires an additional form.)
3. Staff conducts a traffic study to document the number of vehicles and the speed of traffic using the street.
4. Residents are notified about the results of the study and the corresponding speed cushions fee.
5. If residents wish to pursue speed cushions, they notify City staff. If the street is eligible for speed cushions, residents and staff work together to determine appropriate locations. Once locations are identified, staff prepares official petitions showing the proposed locations and the petition boundary area.
6. Residents circulate petitions and document at least 70 percent support from the petition boundary area and 100 percent support from residences within 100 feet of any proposed speed cushion.
7. Residents submit original signed petitions back to the City along with the appropriate speed cushion fee.
8. City staff verifies the petitions.
9. If consensus building is adequate, staff notifies its Contractor to install the cushions as shown on the petitions. Staff will also coordinate the signing and striping according to City standards.
10. If, during petitioning, residents want 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.
11. 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.
12. If, at a future time, residents want to remove one or more speed cushions, they must request and return a City generated petition with at least 51% approval of the original petition boundary area. If approved, residents must pay to remove the cushions.