Study shows steep traffic decline on 520 bridge since tolling

SEATTLE - A new U.S. Department of Transportation study set to be released this week shows commuting over the 520 floating bridge is down by half since tolling began.

The study was conducted as Washington state leaders are deciding whether to slap a toll on the Interstate 90 bridge over Lake Washington.

According to the new data, almost 9 in 10 drivers who stopped using the 520 bridge said they did so to avoid the tolls, which are more than $3.

The study also shows that the impact of the toll is hitting lower-income households the hardest.

Here's the breakdown: drivers with household incomes of less than $50,000 avoid the bridge, while drivers with household incomes of $200,000 or more say they don't mind the tolls. In fact, affluent drivers say their satisfaction while using the bridge has increased.

Another impact of the toll is increased use of mass transit. Some 45 percent of people say they did so because of the 520 bridge tolls.

The study also shows that overall commuting over Lake Washington is down by 20 percent since tolling began.

The new information will go before state leaders Tuesday and Wednesday - before they decide whether to toll the I-90 bridge.