Triptych alternative landscape diagram. Image from Esocoff & Associates.

The moment the Capitol Hill Town Square team finished their presentation, one woman stood up ramrod straight, her hand in the air, an intense, determined expression on her face. The moderator called on her, and her statement was as sharp as her facial expression. This whole notion of traffic calming on Pennsylvania Avenue at Eastern Market Metro was just the wrong thing for Capitol Hill, based on faulty assumptions, she argued. We don’t need traffic to move slower, or put any impediment along this commuter artery from Maryland.

A number of other residents echoed this sentiment, whether in questions, rudely shouted comments from the back, mutterings not entirely under their breaths from a couple next to me, or applause that broke out after questioners asked hostile questions to the project team — mirrored by approximately equally loud applause when other questioners challenged the car-centric assumptions of some other questions.

Many residents of Capitol Hill seem to have made up their minds one way or the other about this project from the moment they heard about it. In fact, EMMCA declared themselves unalterably opposed to a plan long before the team created a plan. That’s too bad, not because we must realign Pennsylvania Avenue around Eastern Market, but because we should decide what to do based on evidence, not dogma, and the evidence isn’t all yet available.

Most people instinctively believe that traffic is like a river. There’s a bunch of water flowing down from a mountain, and running along a stream. Narrow the stream bed, and the water will run into some other river, or flood your house. If you dam it up, the water backs up to create a lake, and nobody wants a traffic lake. However, traffic isn’t like water. It’s more like air, which can expand and contract to fill the available space.

It was clear from the questions that many Capitol Hill residents were basing their opinion on the water mental model. If we shrink Pennsylvania from three through lanes to two, where will the cars go? Will they divert through neighborhood streets? Will traffic back up on Pennsylvania? Will slower-moving traffic create more pollution? What about emergency evacuation?

There’s no particular reason to believe such a change would bring these effects at all. Some drivers may begin taking the Southeast Freeway instead. Some would switch to transit; Metro remains underutilized on the eastern ends of the Orange and Blue Lines. Some would bicycle, given the bike lane the team has suggested adding on Pennsylvania Avenue.

Or, perhaps, the change would make traffic worse or would divert substantial traffic to neighborhood streets. The transportation consultants from Gorove/Slade don’t believe so, and have promised to release their findings. Side streets aren’t designed for speed and even a slower Pennsylvania Avenue would be better than slogging through the stop signs. But we can judge for ourselves once we have all the facts. Driving along Pennsylvania from time to time doesn’t constitute having all the facts.

Residents near Sherman Avenue in Columbia Heights would love to calm traffic through their neighborhood. Commenter angryparakeet wrote, “I’d like to reclaim [this] neighborhood from MD commuters.” It’s surprising and sad that some residents of Capitol Hill see efforts to make their neighborhood a more pleasant place as the wrong direction, closing their minds to other possibilities.

Fortunately, we can without spending millions to redo the plaza. Let’s install the traffic modifications right now. The “Existing Improved” alternative suggests closing the short segments of D Street connecting to Pennsylvania, putting bulb-outs at many of the corners, and narrowing Pennsylvania by about half a lane, turning the third travel lane into a bike lane. We could implement these changes now with some plastic curbs, posts, and a little paint.

Excerpt from the traffic plan for the “Existing Improved” option. Image from Esocoff & Associates Architects. Click for full, larger version.

Let’s try it out for six months or a year. If the change substantially worsens residents’ quality of life, we can reverse it and redesign all three options to retain three travel lanes. If it improves the situation, then we can debate a straight road, an oval, or a rectangle free of the debate over traffic calming.