This post has been updated with comments from SDOT spokesman Rick Sheridan

Back in June, PubliCola reported that the Seattle Department of Transportation planned to build Seattle's first parking-protected cycle track on Dexter Ave. But after cyclists questioned whether cycle tracks made sense on Dexter, SDOT decided to add buffered bike lanes to the road instead.

Now, SDOT is proposing the addition of a two-way, parking-protected cycle track on the east side of Linden Ave N. between N. 128th and N. 145th Sts, completing a missing gap in the Interurban Trail. If SDOT doesn't change its plans and moves to construction on schedule, Linden Ave. will have Seattle's first official parking-protected cycle track.

SDOT Project Manager Connie Zimmerman and Engineer Dave Vijarro presented the project proposal at September's Seattle Bike Advisory Board meeting. The current proposal calls for two five-foot bike lanes on the east side of Linden separated from the parking lane by a three-foot painted buffer. The parked cars would serve a physical barrier between bicycles and cars. SDOT also plans to add improved pedestrian crossings, new sidewalks, and five-and-a-half-foot planting strips to separate pedestrians from bicyclists.

A two-way cycle track presents unique issues with turning at intersections (southbound bicyclists, for example, would find it hard to turn right across two lanes of traffic, for example). SDOT is considering either a four-way bike and pedestrian "scramble" like the one at California Ave and Alaska St. in West Seattle, or a dedicated bicycle signal.

One oddity in the plan is the six-foot painted buffer between the two car travel lanes (which you can see in the center of the 67-foot cross section above). The buffer may be intended to keep the roadway uniform since part of Linden has a 67-foot-wide right-of-way and part of it has a 50-foot wide right-of-way. But it seems like that space could be better used to widen the bike lanes, or the sidewalk, rather than provide an unusable space between cars.

Buffer aside, SDOT's current plans for Linden Ave are a significant improvement over the first iteration, which called for traditional bike lanes on either side of the road. Although the 2007 average daily traffic was only 2,000 vehicles (a traffic level low enough for a bicycle boulevard), Linden has been rezoned for greater density, and SDOT projects a significant increase in traffic. Also, a protected cycle track is a more fitting connection for the Interurban Trail than a traditional bike lane.

SDOT hopes to reach 60 percent design before the end of 2010, final design by next summer, and begin construction of phase one (130th-135th) by September 2011.

UPDATE

SDOT Spokesman Rick Sheridan explained the six-foot painted buffer between car travel lanes. According to him the buffer, "allows drivers to safely back into parking and pull out of it without entering the oncoming lane of traffic.  It also provides the space to install a pedestrian crossing island  between 130th and 135th."