- Public Works
- Braintree Neighborhood Traffic Calming
- Speed Cushions or Humps
Speed Cushions or Humps
Speed cushions and humps have been proven effective in reducing speeds.
A speed cushion is rubber raised surface, typically 3” tall, 6’ long x 7’ wide. They are temporary installations that reduce speed and accommodate emergency vehicles, needing to be removed for winter months.
A speed hump is a permanently installed rounded, raised area of the street, typically 4" tall and 12 to 14 feet long. Neither of these are like the speed bumps you encounter in a parking lot.
Both solutions are designed to be comfortable for drivers going 20 to 25 MPH. The tapered edges minimize jarring. When built with the proper profile, speed cushions or humps are also easily traversable by bicyclists.
Speed cushions or humps are a type of "spot" measure that must be spaced so that drivers go a constant, but lower, speed. As they go over a speed cushion or hump, drivers should be able to see the next one ahead. This spacing encourages drivers to maintain consistent and safe speeds. Without proper spacing, drivers may rapidly accelerate and decelerate at the speed cushion or humps.
Neighborhoods interested in this solution would receive speed cushions for an initial one-year test, the Town would then host a neighborhood meeting to discuss their effectiveness before permanently installing speed humps in their place. Streets with speed cushions already deployed will also have the option of permanently installing speed humps.
- Very effective at slowing speeds
- Relatively inexpensive
- No impact on drainage
- No impact to on-street parking
- Impacts emergency vehicle movement by 2 to 9 seconds per speed hump
- Must be signed and marked to give advance warning to drivers and snowplow operators
- May generate additional noise If not spaced properly
- Speed cushions will be used initially in new neighborhoods. After a one-year period, the Town will meet again with neighbors to review speed cushion effectiveness and popularity before removing speed cushions and replace with permanent speed humps.