Slower Seattle speed limits will reduce congestion, proponents say

The Seattle City Council’s Sustainability and Transportation Committee met Tuesday to hear, and craft, the argument to reduce Seattle speed limits.

It was a time to amend and discuss legislation that will soon head to the full council for a vote. In the meeting, council members Mike O’Brien, Kshama Sawant, Rob Johnson and Tim Burgess went over details of the legislation currently being written.

The general sentiment among the council members was that lowering the speed limit would result in fewer fatalities and injuries when it comes to collisions between cars and pedestrians / cyclists. It's part of the city's move to Vision Zero — a program to eliminate accidents on city roads.

“Speed is a contributing factor in making it a more severe crash,” Seattle Department of Transportation Director Scott Kubly said.

“Not only does speed increase the likelihood of crashes but it increases the severity,” Darby Watson with SDOT added.

If the council does lower Seattle speed limits, the city could begin changing signage around town as soon as November, the Seattle Times reports. That will come at the cost of $200 to $300 for each sign. There will be roughly 500 signs to switch out.

Lowering Seattle speed limits

In short, the council’s move to lower Seattle speed limits from 30 mph to 25 mph on arterial roads, and drop the limit from 25 mph to 20 mph on residential streets. These changes will only affect roads in Seattle’s inner core — including downtown and neighboring communities. But the remaining Seattle streets outside of the inner-core will eventually be addressed. If the lower Seattle speed limits pass, while that change is put into place, outlying roads will be studied to assess where their limits can be lowered as well.

The city center is of the highest concern for the lower speed limits because that is where the majority of incidents between vehicles, bikes, and pedestrians occur.

But the issue of traffic congestion was also raised, to which the idea promoted is that fewer accidents will equate to less congestion.

“Sometimes this gets phrased as a trade-off between more congestion and safety. Actually, slower speeds don’t necessarily mean more congestion …” O’Brien said.

“This actually helps reduce the crashes that we have,” Kubly said. “So if the human side of this, if the safety side of this doesn’t appeal to you, generally when we have a crash, it takes a very, very long time to clear … beyond just the speed, it will actually improve flow.”

The council was also informed the following about Seattle speed limits:

  • Speeding contributes to 25 percent of fatalities annually.
  • 13,000 collisions each year on Seattle streets, of which 27 percent were on non-arterial roads, and 73 percent were on arterial roads.
  • 9/10 bike and pedestrian collisions result in injury.
  • Pedestrian / bike collisions make up 7 percent of crashes, but 47 percent of fatalities.
  • There are 450 pedestrian collisions citywide annually.
  • 70 percent of pedestrian deaths are people ages 50 years or older.
  • Seattle is the only city in King County with a default speed limit that is higher than 25 mph.
  • The proposed reduction in speed limits will apply to 2,400 miles of streets.