The bridge's heavy traffic has created three problems:

1. Volume: Experts predict a 45 percent increase in trips by 2020, resulting in 275,000 vehicles a day crossing the bridge.

2. Capacity and access: The six-lane bridge is a bottleneck for vehicles entering from the eight-lane Beltway. Four lanes from the Beltway and three ramps merge into three bridge lanes in each direction.

3. Safety: Accident rates on the bridge are twice as high as those on other segments of the Beltway.

Options: Studies show that it is not economically feasible to rehabilitate the bridge. This would compound existing congestion and disrupt vehicle and marine traffic for several years because of extended lane closures. Yet, experts now agree that the bridge has only six years left before traffic restrictions would need to be imposed. These could include weight restrictions and the banning of trucks.

The Proposal

The number of lanes needed for the new bridge has been greatly disputed. Many Alexandria residents favored a less intrusive 10-lane plan. In the end, officials decided that 12 lanes would meet traffic needs more effectively.
Safety: Shoulders will reduce the rate of accidents and improve accident management.	Merging: A lane in each direction will support safer merging.	Bridge design: Although a design for the new bridge has not been finalized, specifications require arches designed to mimic other Washington bridges.	Other features: A pedestrian and bicycle path will connect to the Mount Vernon Trail in Virginia and the proposed Potomac Heritage Trail in Maryland. Also, lanes could be reconfigured to accommodate HOV or express traffic.

Existing Bridge

Safety: The accident rate on the bridge is twice the rate elsewhere on the Beltway. Officials say the absence of shoulders makes for unsafe conditions. Emergency vehicles often have trouble reaching accidents.

Merging: There are no merge lanes between nearby interchanges and the bridge, causing unsafe merging.

Lanes: Beltway approaches are four lanes in each direction that must narrow to three on the bridge. This creates a bottleneck and an average weekday backup on the Beltway of one to six miles.

Other limitations: There is no room to widen the existing bridge to accommodate car-pool, bus, transit or pedestrian/bicycle lanes.