@scoot 130023 wrote:
For a few reasons, I’m not a huge fan of grade separation for this intersection. First, it would require new infrastructure.
My solution does not require any new bridges or tunnels, but does require reconfiguring a bunch of roadway surface and probably some retaining walls and such. (and NPS…)
A tunnel under Lynn Street, unfortunately, presents a number of challenges due to the topography. For eastbound cyclists going to Key Bridge, they will either still need to cross the IoD as it is now or take the tunnel and then turn left. Given the elevation differences and the short distance to the GWMP off ramp, I am not certain it is possible to build an ADA acceptable ramp from a hypothetical tunnel to the Key Bridge without some sort of zigzag or something. I believe it’s at least a 7-8% grade. And that would eliminate the opportunity to reconfigure that ramp, because moving it would only increase the grade of any connector from the tunnel. And coming up a grade to the ramp crossing may make sight lines worse for everyone.
I am guessing a good portion of people on bikes will opt to continue to take the left across the IoD than to go all the way down through the tunnel, sharp left and all the way up to the bridge. Or…they will game the light and choose one or the other based on light timing. That’s what I would probably do.
A tunnel only helps for a fraction of people dealing with the intersection, while my solution improves it for everyone.
For instance, Northbound cyclists and peds on Lynn will still deal with the IoD as it is and the right-on-red cars. Southbound cyclists and peds on Lynn will still have to deal with right-on-red cars who are looking the other way. We can try to force southbound cyclists to take Ft. Myer Drive, but going to the Bikeshare station is a lot shorter along Lynn Street than all the way around, so we’re not going to stop people on bikes from using that sidewalk in both directions.
