by Cathy Tuttle
January 24, 2016
SNG Speed Hump Study On Lake City Greenway
Let's hear it for the lowly speed hump!
Seattle is poised to soon get thousands of these amazingly effective speed control devices near our schools and parks!
Speed humps, often called speed bumps**, are quick and inexpensive to install, and when installed correctly, force drivers to slow down.
Do speed humps work?
Seattle Department of Transportation (SDOT) started installing speed humps as part of neighborhood greenways and Safe Routes to School projects a couple of years ago. Wisely, SDOT measured speed data to track hump effectiveness.
Total speeding on the streets near three elementary schools dropped between 79 – 88 percent after speed humps were installed, and high-end speeding was nearly eradicated, and there was a 90 percent drop in aggressive drivers traveling more than 10 MPH over the speed limit.
Speed is the most important factors that determines how seriously a person is injured in a collision and, of course, whether the collision occurs in the first place. So yes, speed humps work.
SDOT Safe Routes Speed Hump Report
What is a hump?
Technically, speed “humps” are different from the speed “bumps” you often encounter in parking lots. Built correctly, humps are more gradual and are not meant to bring people to a nearly complete stop. If you are driving or riding a bike at 20 MPH or below, you will not need to adjust your speed to go over them comfortably. If you are moving faster than 20 MPH, however, you will need to slow or face a jolt. And unlike with some speed bumps, the speed humps are not so sudden that they are likely to cause someone on a bike to crash.
Seattle’s speed humps will save lives, and they will prevent many people from serious and sometimes debilitating injuries.They will also make neighborhood streets places where people of all ages can live, have fun and get around on foot and bike.
Why is Seattle getting many new humps now?
In 2015, Seattle Neighborhood Greenways (SNG) staff came back from a Vancouver BC Study Trip with Commute Seattle, excited to share best practices. Among our take-aways was a Vancouver policy of putting speed humps on all non-arterial streets at EVERY school and EVERY park. SNG staff worked with SDOT Safe Routes to School coordinator Brian Dougherty and Parks staff on adapting Vancouver speed hump policies and we're pleased to report Seattle has just now adopted similar policies!
Expect slower speeds soon where our children play and go to school. We have the tools to make our streets safer, and the speed hump is one of our most powerful tools in our safety toolbox. We can't wait to see more of them!
**You may hear the terms speed humps and speed bumps used interchangeably by traffic safety professionals. Speed “humps” are actually the official term but according to our friends in Portland traffic engineering, the signs that said “Humps Ahead” were frequently stolen by the public but “Bumps Ahead” were left to perform their traffic calming duty.