Officially more expensive than busing across Lake Washington on Sound Transit, it could potentially cost drivers up to $6.85 round-trip to use 520 as their primary commuter route. Further suggestions indicate that the rate would be variable throughout the day and week, with some tolls as low as $0.75. Currently 115,000 vehicles use the bridge daily.

Highway 520 tolls:4 options
TOLLS TO CROSS THE FLOATING BRIDGE would be less if they begin in 2010, or more if the state waits until 2016, when a new bridge is supposed to be finished, a state study says. These examples are for one-way travel.
Toll current bridge in 2010, new bridge in 2016: Morning peak $2.15; afternoon peak $2.95; midday $1.05.
Toll new 520 bridge in 2016: Morning peak $3.05; afternoon peak $3.80; midday $2.10.
Toll new 520 and existing I-90 bridges, in 2016: Morning peak $2.60; afternoon peak $3.25; midday $2.10.
Toll 520 bridge in 2010, and I-90 bridge in 2016: same as preceding option.

* ALL PRICES IN 2007 DOLLARS (Via Seattle Times ^[1])

When parts of I-5 closed for repair, commuters utilized a variety of different methods to avoid long backups. These methods consisted of carpooling, working from home, using public transit, and driving during off-peak hours. I wouldn’t be surprised if more companies introduced employee bus passes/rideshare options, or perhaps offer commuter buses ala Microsoft’s Connector.