Speed Cushion Requests

Speed cushions are traffic calming devices that use vertical deflection to slow motor-vehicle traffic in order to improve safety conditions. The use of vertical deflection devices is most commonly found where vehicle speeds are mandated to be low, usually 25 miles per hour. 

Speed cushions are either speed humps or speed tables that include wheel cutouts to allow large vehicles to pass unaffected, while reducing passenger car speeds. They can be offset to allow unimpeded passage by emergency vehicles and are typically used on key emergency response routes. Speed cushions extend across one direction of travel from the centerline, with longitudinal gap provided to allow wide wheel base vehicles to avoid going over the hump[1].  For more information on speed cushions, visit the NACTO Urban Street Design Guidelines.

Ongoing Projects

Bellefonte Avenue - Between Route 1 and Dewitt Avenue

Completed Projects

• Russell Road - 85th percentile speeds decreased by 21% in the southbound direction and 18% in the northbound direction 
• West Abingdon Drive - 85th percentile speeds decreased by 30% on this roadway from 35.2 mph to 24.7 mph 
• Martha Custis Drive - 85th percentile speeds decreased by 21% on this roadway from 30.4 mph to 23.9 mph 

Eligibility

ELIGIBLE 

Local Streets 

• 85th percentile speeds exceeding the speed limit by 5mph AND
• Minimum of 500 vehicles per day AND
• Minimum segment length of 900 feet

Residential Collectors 

• 85th percentile speeds exceeding the speed limit by 5mph AND
• Minimum of 1500 vehicles per day AND
• Minimum segment length of 1,200 feet

INELIGIBLE   

• Any street other than a Local or Residential Collector (street map classification map)
• Denial of a similar request within past 5 years of data collection
• Street is currently in design as part of another Complete Streets project
• Streets that have a Fire Department house or hospital emergency entrance located adjacent to the project area
• Streets that are major transit route  
• One way streets must have a travel lanes of at least 9 feet and two way streets must have travel lanes that total at least 18 feet 
• Street is less than 900 feet long or is a dead end
• Street has stop signs 300' apart or less
• Private Streets (the City only maintains public streets)

Additional Considerations that can impact eligibility or implementation
 

• Emergency vehicle, schools, bus and truck routes
• Sight distances
• Curbs and gutters
• Grade
• Curvature of street
• School bus route or transit routes
• Adjacent arterials
• Residences fronting on street
• On-street parking
• Proximity to a stop sign
• Safety considerations
• Resurfacing schedule
• Excessive traffic diversion to other neighborhood streets
• Budget, feasibility, number of locations approved per year
• Neighborhood support of project
   

Process 

1. Review eligibility criteria and if eligible, fill out and submit application for speed cushions
   
   Individual  
       • Gather signatures of 5 people within the project area in support of request and identify yourself as the project champion (main point of contact)
   
   Civic Association 
       • Assign a project champion or chair will assume role 
2. City will approve or deny application based on the Speed Cushion Guidelines criteria
3. If approved, City will collect the following data:
       • Speed
       • Crash
       • Volumes
4. If eligible criteria is met, project champion is required to notify each household in project area with flyer distribution and provide signatures in support of project from 70% of addresses on the block - one per household – in project area identified by City staff (signature page).
5. Condominium and apartment buildings incorporating 25 or more households will not be required to get signatures from all the residents, but rather the written support of the traffic calming plan by the condominium association or property management company, respectively (multifamily signature page).
6. City engineers will determine the exact location of the speed cushion(s) per installation guidelines below.
7. City staff will inform project champion & civic association of eligibility and location for installation and may choose to present project at a public hearing or civic association meeting.
   If  so, project champion will notify residents of the street via flyer or email
8. City staff will prioritize request for speed cushion based on speed and safety considerations to determine timeline for installation, schedule installation and notify civic association and project champion prior to installation and install cushions
   Project champion will notify residents of the street via flyer or email
9. If appropriate, staff may elect to collect data on adjacent streets

Online Application

Installation Guidelines*  

• Placement of a raised speed cushion shall be at least:
• 5 feet from any driveway or curb cut on a local street (additional clearance may be required for curb cuts utilized by trucks)
• 15 feet clearance from either side of a hydrant
• 150 feet from an intersection that is controlled by a stop sign or signal
• 75 feet from an uncontrolled intersection
• 150 feet from a curve in the roadway
• 250 feet minimum spacing between cushions
• 2 feet from a manhole or utility cover on approach or 6 feet after the cushion
• Approval required from Alexandria Fire Department

*Detailed engineering analysis will be conducted for each project per the City's engineering team

[1]  NACTO Urban Street Design Guidelines 

Existing speed humps and tables are grandfathered in to this program but will be replaced with speed cushions with roadway resurfacing.