Source: US DOT.
The George Washington Bridge (GWB), linking Manhattan to New Jersey, is one of the most heavily used bridges in the world, with daily traffic between 275,000 and 300,000 vehicles. This accounts for more than 100 million vehicles per year. Completed in 1931, a second level containing six lanes was added in 1962, making George Washington the world’s only 14 lanes suspension bridge. The bridge is facing two major types of congestion problems:
- First, it supports commuting flows between Manhattan and the New Jersey suburbs. This pattern is clearly shown in the above figure, where eastbound flows (New Jersey to Manhattan) are more prevalent in the morning, while westbound flows (Manhattan to New Jersey) are more prevalent in the afternoon and the evening.
- Second, the bridge is one of the crucial links along the Boston – Washington corridor (Interstate I-95), which imposes a substantial amount of truck traffic (above 23,000 trucks per day).
There is thus an overlap of local and regional traffic flows, stressing the physical capacity of the bridge. In addition, the eastbound access to the bridge is subject to toll, which creates a significant backlog and delays; the users are forced to assume both the monetary (toll) and time (delays) costs of toll collection. To mitigate the situation, an electronic toll system was established with reserved toll lanes. About 85% of the vehicles using the toll now have an electronic tag.