The state has seen far more people use the I-405 express toll lanes than it forecasted.
At the same time, the state’s forecasts for the number of carpool users have proved to be dismally off.
Since the lanes opened in September, the total number of trips — including free carpools as well as those who pay a toll to use the lanes — is coming in at 45 percent above projections, according to a recent annual report on tolling by the Washington State Department of Transportation.
Most pay a toll.
More than 5 million toll-paying trips have been logged. That’s already 51 percent higher than the estimate planners penciled in for the entire first year of operation.
One by-product is a lot more money coming in — $10 million and counting. That running total already tops the predicted take for the entire first year by about three times. Some of the money will pay vendor contracts; the rest will go to future I-405 projects.
Meanwhile, there’s been a lackluster number of registered carpools.
Carpool requirements are more restrictive with tolling. Carpools must sign up for a Good to Go account, purchase a Flex Pass, and have at least three people during peak commuting hours in order to use the lanes toll-free.
Projections for such registered carpool use are off by more than a half-million trips so far, despite efforts that gave away over 33,000 free Flex Passes.
The state data doesn’t delve into occupancy details — for example, the number of vehicles with two occupants that paid a toll to use the lanes during peak hours.
Past studies have shown carpool rates can go down when the incentive to buddy up is taken away. Tolls and low gas prices can be among those factors. Snohomish County drivers already were less likely to carpool.