The case for rebuilding 11th Street Bridge in D.C.

By Robert Thomson
Sunday, May 2, 2010; C02

Rebuilding the 11th Street Bridge will create a new transportation system over the Anacostia River that serves freeway and local traffic on separate spans. But Christopher Herman and some other city residents worry that too much of that traffic will wind up on their streets.

I asked the District Department of Transportation to respond to the critique by Herman that appeared in the column last Sunday.

Dear Dr. Gridlock:

Whether the 11th Street Bridge project were built or not, traffic through the corridor it serves will continue to increase over the next 20 years.

The project provides the District with the best options for managing that traffic.

Unfortunately, Mr. Herman's letter appears to misrepresent and take information about the 11th Street Bridge project out of context.

Contrary to his assertions, the project will benefit both D.C. residents and commuters. Key among these benefits are new connections between the Southeast-Southwest Freeway and D.C.-295/Anacostia Freeway, separation of freeway and local traffic, and improved alternate travel options.

The two new freeway bridges will have four lanes in each direction just as the current bridges do. However, improved connections and design will allow traffic that crosses them to flow more efficiently, with direct access to both directions of the two freeways without first having to travel on local streets such as Pennsylvania Avenue, Good Hope Road and Minnesota Avenue SE.

With two lanes in each direction and a 16-foot-wide shared bicycle and pedestrian path, the local bridge will serve as an extension of the local street grid. This will better connect District neighborhoods and improve safety by eliminating the current need for local traffic and transit buses to mix with freeway traffic to cross the river.

The installation of rails in the outer lane in each direction will provide the additional option of future streetcar connections.

As a result of these improvements, studies predict that almost 50,000 more vehicles per day will travel the three new bridges by 2030 than would have used the existing two. This equates to less than 10 additional vehicles per bridge lane per minute during peak travel hours. And the majority of these are vehicles that would otherwise have continued to use local streets to navigate between the freeways.

If these benefits weren't enough, the new bridges provide a needed alternate evacuation route from the Capitol and environmental investments lacking on the existing bridges, such as storm water drains.

Project design has been altered slightly to benefit residents and commuters by, among other things, lowering the height of some freeway ramps and reducing traffic impacts of construction by allowing continued use of the existing bridges while the new bridges are built between them. In addition, designers determined that building the bridges on new piers and piles rather than the old would extend the life of the new bridges while reducing their long-term maintenance costs.

The 11th Street Bridge project has for years been included as a priority project on District and regional transportation plans in recognition of the many important benefits it will provide residents, commuters and the region.

-- Greer Johnson Gillis, Deputy chief engineer, District Department of Transportation

David Alpert, an advocate for better urban planning who founded the Greater Greater Washington blog, shares some of Herman's concerns about neighborhood traffic and also worries about whether the local bridge really will be local.

"My fear is that if traffic is slow on the freeways and across the bridge, a lot of drivers will just get off at one end, take the local bridge, then get back on," Alpert wrote in an e-mail. "The effect would be to create another backup on the local bridge, depriving locals of the actual opportunity to use the local bridge."

He thinks the District should limit where drivers can get on or off the local bridge.

I think the District should monitor the new traffic patterns and respond to specific problems. But it will take a lot of congestion to persuade long-distance commuters to abandon their new freeway links in favor of the local bridge, with its two-way traffic and streetcars.

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer's name and home community. Personal responses are not always possible.

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