Wallingford and Green Lake Community Councils made a request to SDOT back in 2007 to reconfigure Green Lake Way with 3 goals:
- Maintain or improve throughput for vehicles at the intersection of 50th and Green Lake Way
- Connect Stone Way bike lanes to the Green Lake Way bike lanes around the lake
- Restore lost pedestrian crossings between Tangletown and the park
As SDOT typically does these days, they accepted the bike and pedestrian goals and then threw out the goal of maintaining vehicle throughput. The worst part of that was that they eliminated the two lane car queue for getting onto Stone Way from Green Lake Way, backing traffic all the way up to the lake.
I’ve been ruminating on the design problem ever since. Then, in a dream last night, it came to me! Yes, it’s time for me to go back on my OCD blockers. The basic idea is to:
- Restore the 2 lane car queue for Green Lake Way south bound all the way back to 52nd, plus allow it to grow further in the mornings as necessary. This should allow many more South bound vehicles through the light cycle, bringing throughput close to what it was prior to the 2013 redesign.
- Keep cyclists to the side of Green Lake Way all the way to the light when going South bound on Green Lake Way, then change the signal timing so that bikes get to go before the traffic continuing onto Green Lake way. This should make it safer for cyclists going south bound onto Stone Way while also giving cyclists the flexibility to go onto 50th or continue onto Green Lake Way.
- Finally, tweak the light going north bound so cyclists and pedestrians don’t conflict with cars.
In picture form, here is how things work today, green is bike lanes, black is paint for cars. The 5 signal movements are colored with cyclist movements shown via green arrows and vehicle movements shown via black arrows:
Here is the proposal. The only change to the pavement is north of the intersection. The bike lane on Green Lake Way south bound stays on the side all the way to the light, and the cars are fully separated between traffic going on Green Lake Way and Stone Way / 50th East bound. Most changes are made to the light sequence itself, with dedicated bike signals allowing bikes to go separately from vehicles:
Here are the changes by turning movement (numbered circles above):
- When 50th West bound goes, so does the right turn from Stone Way north bound to 50th East bound. Pedestrians can’t cross 50th at this time, so it’s the safest time to have cars turn right
- The 50th East bound light has no changes from today
- This is the big change: Instead of Green Lake Way north bound going next, Green Lake Way going to Stone Way goes next. This includes all the bike traffic on Green Lake Way south bound, including the traffic continuing onto Stone Way. This has several benefits:
- Bikes do not have to go between traffic lanes on Green Lake Way south bound approaching the light
- Bikes can continue onto 50th West bound or Green Lake Way south bound, both of which are blocked today
- Bikes no longer need to travel in the middle of car traffic
- This is a continuation of the the Stone Way turning signal. Cyclists going South are stopped and cyclists going North get to go. Vehicles get to go both South bound and North bound, but don’t turn right on 50th anymore, preventing conflicts with cyclists going North and pedestrians crossing 50th.
- Finally, the Green Lake Way north bound takes its turn going, the same pattern that currently happens in step 3 today (the first graphic), except cars have a separate queuing lane on Green Lake Way south bound and are no longer blocked by traffic going onto Stone Way south bound.
Here are the changes to the paint in more detail, showing Green Lake Way south bound as it approaches the light:
As far as I can see, everybody wins. Vehicles gain a 2 lane queue on Green Lake Way south bound while approaching 50th. This should prevent traffic from backing up to the lake and greatly improve throughput at the light. The only semi-loss is that left turns onto 51st would no longer be allowed, but as that’s mostly cut through traffic anyway.
Cyclists will gain by having fewer conflicts with vehicles, both while queued at the light and while traveling. Cyclists will also be able to continue onto 50th or Green Lake Way when going South on Green Lake Way instead of being forced onto Stone Way. Pedestrians will be able to cross 50th without having cars turning right at the same time as they are walking.
Wow, you read all the way through? Clearly you also need some more meds. What are your thoughts?