Dexter Avenue North in Seattle’s South Lake Union neighborhood should be put on a diet.
It serves as a cycling superhighway, connecting bike-loving Fremont, Wallingford and Greenlake with downtown via a dedicated bike lane used by thousands of commuters a day. But the poor design of Dexter between Mercer Street and Denny Way is a proven hazard to cyclists (see Seattle Times stories on the 2011 death of Michael Wang and the serious injury of Brandon Blake in July).
The problem, as Seattle Bike Blog’s Tom Fucoloro described in a post last month, is that Dexter’s wide, four-lane design encourages speeding. The four-lane design has an additional problem, requiring southbound drivers turning left into the tech hub of South Lake Union to cross two lanes of speeding traffic, as well as the busy bike lane. As a regular biker and car driver on that route, it’s clear that turning drivers focus on the two traffic lanes, and not the bike lane.
Seattle Department of Traffic traffic engineer Dongho Chang agrees that stretch of Dexter is troublesome, and is on the city’s list for study next year. The road has more capacity than it needs (with 13,000 vehicles a day, per a 2011 count), which encourages speeding, Chang said. It’s a good bet, in my opinion, the recommendation will be a road diet — reducing four lanes to three, one lane of traffic each way with a center turn lane.
I’m sure that will prompt outcry about a bogus “war on cars.” So let’s look at the evidence: What has happened with other road diets?
With Stone Way North, dieted in 2008, an SDOT before-and-after study found traffic volumes stayed relatively constant, but collisions and injuries dropped as the rate of speeding fell, and and traffic wasn’t diverted on side streets (one measure of cars dodging a clogged roadway).
Ditto for West Nickerson Street, according to an SDOT report, between the Ballard bridge and Fremont. Fewer speeders and collisions, constant traffic volumes. West Seattle Blog reports about Fauntleroy Way Southwest follow that trend.
Based on the evidence, a road diet on Dexter Avenue North would serve a double purpose: safely connecting the existing bike lane with the future Amazon.com-funded 7th Avenue cycle track (map at left), and enhancing pedestrian safety. That second point is critical for a booming neighborhood with increased residential density, and because the street grid will be reconnected across Aurora Avenue North when the Highway 99 tunnel opens.
When the grid is reconnected, the city has inherent interest in ensuring a walk directly from South Lake Union to the Seattle Center via Harrison Street won’t involve crossing speeding four lanes of traffic on Dexter.
Road diets are a legacy of Mayor Mike McGinn. I dislike other parts of his record, but give him credit for forging ahead with road diets despite political blowback. Well-chosen road diets make the city a better place to live, walk, bike and, yes, drive. Dexter Avenue North is an obvious candidate. I hope it happens.
This blog post, originally published at 6:25 a.m. on Sept. 16, 2013, was corrected at 9:35 a.m. An earlier version incorrectly said that Mike Wang died in 2001.