New, greener, safer, better design coming for 15th and W
15th and W Streets and New Hampshire and Florida Avenues, NW all come together in a large, barren expanse of asphalt that Stephen Miller nicknamed the Death Star after a driver killed a pedestrian there in 2009. But DDOT is on the side of the rebels and is striking back with a redesign.
None of the roads at this intersection are very wide or carry much traffic. However, traffic engineers in years past made the block between V and W function like a set of freeway offramps. The lanes merge to a narrower 15th Street and a gradual slip lane onto Florida that encouraged drivers to make the turn at high speed. Chevrons mark off a large tract of pavement between the two.
After the 2009 fatality, DDOT quickly moved to install temporary curbs and posts to slow traffic at the corners. On Wednesday, they presented preliminary options for a permanent solution to a committee of the local ANC.
Both options would limit traffic in the block of 15th from V to W only 2 lanes, moving back the 3-lane to 2-lane merge point to the block between U and V. At W Street, one lane would continue up the hill on 15th, while the other would let drivers turn right onto either Florida Avenue or W, in more of a traditional intersection.
The 2 options only differ in the location of the newly-created green space. One option puts it mostly on the east side of the street, while the other divides new green space between the east and west sides.
These options have safety trade-offs. Keeping the roadway on the left (left-hand image) makes the lane shift on 15th more gradual and makes speeding easier, but it also allows for a larger triangular pedestrian island in the middle of the intersection. Shifting the roadway to the right (right-hand image) forces drivers on 15th to slow down more as they approach the hill, but leaves a smaller pedestrian island.
Both proposals add numerous bulb-outs at the crosswalks just as the agency has included on H Street NE and other places around town. In these places, the curb juts out toward the travel lane and reduces the distance pedestrians must spend vulnerable in the roadway while crossing the street.
The design also extends the 15th Street cycle track into this area. Right now, the 2-way track ends at V Street. Riders heading northbound have to cut across traffic to a bike lane on the east side of the street (or just share the lane), while riders southbound can't legally use 15th in this area (though many do anyway).
The part of 15th going up Meridian Hill now has two bike lanes, both northbound, one on each side of the street. DDOT's original hopes for the 2-way 15th Street cycle track included having it stretch to Euclid, the northern edge of the park. DDOT bicycle program head Jim Sebastian says that when DDOT rebuilds the "Death Star" intersection, they will also complete a continuous 2-way bicycle facility from U to Euclid.
DDOT could just build the cycle track in this intersection along the edge of the roadway, separated with poles, as with the rest of the cycle track today. Other options, though, elevate it up to sidewalk level like many European cities do. The tree boxes would still separate the track from the sidewalk, but then one of a few different curb treatments would divide it from the roadway.
At the meeting, DDOT planner Gabriela Vega said the agency was still weighing the pros and cons of the last three designs' barriers between the cycle track and the parking lane. The barriers in the last three designs all include permeable pavers that allow the ground to absorb more stormwater.
Renderings show treeboxes between the sidewalks and streets including rain gardens to trap stormwater and "flow-through planters," where water that lands in one treebox can gradually flow to the next as it runs downhill, feeding more than one tree.
If those treatments make the trees extremely verdant, the intersection could ultimately look something like this:
Even while the trees are growing, it'd be a huge improvement over today:
Many years ago, DDOT had considered an unsignalized roundabout for the intersection. In 2008 we published a proposal of what that might look like. Back then, the agency responded that they had dropped the idea of a roundabout.
When asked at Wednesday's meeting why a roundabout was not under consideration, Vega said DDOT's traffic models showed that a roundabout could not accommodate the traffic volumes of both 15th Street and W Street.
The designs DDOT presented are preliminary concepts. The agency will update the ANC again in a few months with refinements. DDOT is still seeking input, especially on the cycle track separation options and the roadway alignment options mentioned above.
- Consumers say they like trains. Why don't economists care?
- With Metro, "on time" doesn't mean what you think it means
- Alexandria has identified locations for its next 16 bikeshare stations
- To bike without worrying about nearby cars, I'm happy on the MBT
- There's history to behold on some of DC's manhole covers
- See the beginnings of the Purple Line in Silver Spring
- Transit to Wolf Trap will still run through West Falls Church