It's hard for me to come up with a new wish list, when the previous ones have made so little progress (though Jeff may give his own list) so I decided to follow a theme of only looking at bridges. Not only does it give me a limited set of possibilities, but it also allows me to focus on facilities, which admittedly is what I find more interesting. So over the next 12 days, I'll be talking about the 12 bridges over the Potomac and Anacostia that are at least partially in D.C.*
That doesn't include the American Legion Bridge, which I talked about here. You probably won't be able to bike across that bridge until a new bridge is built, even though I've heard that engineers in Maryland have claimed a bike/ped bridge could be suspended underneath the existing span (like this bike/ped bridge in Austin pictured below) without interrupting traffic.
The basic philosophy is that a bridge should give a cyclist 3 easy options on both sides. On each side, cyclists should be able to quickly turn upstream, quickly turn downstream or continue into the interior. See the picture at right for a general idea of what this flow should look like (the blue is water, the green arrows are the bike/ped routes). This gives a cyclist 9 possible routes.
In addition, the distance one has to go to get from the bridge span to the street grid or a bike trail should be as limited as possible. ADA rules require a maximum slope with landings that can require long ramps - which makes sense - but ideally those ramps should not be momentum stealing switchbacks but long smooth approaches with long sight lines and no sharp turns.
BTW, I recently read this presentation that points out that there were 7 additional Potomac River crossings planned in the '70's that were later deleted from plans. Unfortunately, the presentation for the Northern Virginia Transportation Authority is devoid of any bicycle or pedestrian concerns and is focused on moving people outside the beltway. The only transit mentioned is VRE and the Dulles Rail project.
*I'm counting the 14th Street Bridges as one bridge and I'm ignoring railroad bridges and Todd Bridges.