20’s Penty For Us from Streetfilms on Vimeo.
The speed limit on residential streets in Seattle is 25 mph. That’s not so bad, considering I have lived places where it is often much higher. But could it be better?
This Streetfilms video is about a movement in the UK to lower the speed limits in all residential areas to 20 mph. That extra five miles per hour in Seattle is significant. The odds of a pedestrian death from a vehicle traveling 20 mph is about 5 percent. Once that vehicle gets to 30 mph, the odds jump to around 40 percent. At 40 mph, your odds are a terrifying 85 percent. So 25 might be a good start, but getting down to 20 would be way better. The safety increases are dramatic, and the time added to vehicle trips is negligible.
Lowering the speed just 5 mph would also decrease conflicts between bikers and cars on residential streets. While not nearly as terrifying or prevalent as conflicts on faster arterials, bikes typically travel at least 10 mph under the residential speed limit, which causes the occasional conflict (in my experience, a car that just cannot wait and starts honking and revving the engine). If the speed limit were 20, my 10-15 mph speed would not seem all that slow. Though I’m sure the biggest jerks will still honk and otherwise harass bikers. But every little bit helps.
What are your thoughts on lowering the residential speed limit throughout the city?
6 responses to “20’s Plenty: Lowering residential speeds to 20 mph”
It seems to me that residential speeds are controlled more by the physical design of the road than the legal limit. Lane width, density of intersections, and calming devices (painted intersections, roundabouts, etc.) limit speeds much more effectively than a posted (or unposted) limit.
Definitely. And the city has been doing good work designing residential streets to welcome speeds lower than 25. I think it would be good if the city could outwardly state that 20 is now the limit so drivers have that number in their heads. After all, there are many residential streets without roundabouts and other similar devices, and I see people speed up to 25 for a block, slow down at the intersection, speed up to 25, slow down, etc. It’s a strange way to drive, but it happens.
I also meant to add that roundabouts and speed bumps, etc are expensive, and it will take a while for the city to get them all in. Meanwhile, a simple change in the across-the-board residential speed limit shouldn’t cost too much…
That’s certainly true, as is your comment about cost. I guess I wonder how many people even know that 25 is the limit, since it’s only rarely posted.
That’s a good question. I had to look it up to write this article, for example, because I didn’t know. But if the city were to lower it, a lot of people would hear about it in news stories, and it could start a good conversation about the difference between 25 and 20 on pedestrian survival rates, make people think about speed in terms of pedestrians, etc. Or drivers might just get angry and throw a tantrum (This plan is going to add 2 seconds to my commute! It will be chaos!). Who knows.
Thanks for all the great posts, Tom. Great idea! This should be implemented city-wide on all neighborhood streets. I’ve asked SDOT for help in reducing motorist’s speeds on our local street and they countered that they follow state law and that they rely on motorists to use common sense when motoring through neighborhoods, ha! That certainly does not work well for us where motorists routinely speed through at 30-35mph – and our street is a designated “signed bicycle route” to/from Columbia City (we also don’t have sidewalks)! It would help us out a lot if motorists slowed down and shared the roadway. I’m not sure what it would take to get the state involved but when I’ve e-mailed them asking for help or guidance, they counter it’s Seattle’s job to enforce the speed limit and that I should contact them. It’s a never ending circle.