Humps, Bumps and Cushions

May 23, 2014 7:15am


This post started with a simple question from reader Robin who asked “Do you know what’s happening with the removal of the traffic humps on 56th (between Latona and Meridian)? Are they going to be replaced with speed bumps ?”

We asked the Seattle Department of Transportation Robin’s question but it also brought up a greater question: what is the difference between speed humps, bumps and cushions?

First the answer to the question from Robin about the speed bumps on 56th between Latona and Meridian. According to the Seattle Department of Transportation:

“The humps referred to on N 56th Street were actually two temporary (rubber) speed cushions that will be replaced with permanent speed cushions. The corridor is slated to be repaved so we took this opportunity to replace the temporary cushions with more durable permanent cushions. The construction work is scheduled to commence this June.”

And to the question that I’m sure you are all asking, here’s your answer from SDOT:

Speed bumps  are small bumps you’ll typically see in a parking lot that require drivers to almost come to a complete stop to drive over safely.

Speed humps are larger humps you’ll see on a residential street that drivers are able to safely drive over at 15-20 mph.

Speed cushions are a series of smaller humps installed across the width of the roadway. These are typically installed on arterials or residential street fire routes (allowing for emergency responders to travel over the humps without sustaining damage to the equipment and personnel on board their vehicles).