In a new state study, the proposed express toll lanes on I-405 will produce less revenue and lead to more traffic congestion than first thought by WSDOT officials.

Earlier this year, the legislature authorized WSDOT officials to deviate from the original I-405 Master Plan and create an express toll corridor between Bellevue and Lynnwood. However, opponents were able to convince lawmakers to include a third-party feasibility study before construction.

Cambridge Systematics, INC. was chosen to conduct the study and present the findings to the Washington State Transportation Commission (WTC). WTC officials have not published the study yet but it is complete and it is available here: Eastside Corridor Independent Traffic and Revenue Study

Among the results are perhaps these most significant key findings:

  • “Narrower Range of Revenue Outcomes than Prior WSDOT Forecast.”
  • “Traffic growth drives revenue growth.”
  • “Demand will exceed capacity.”

These findings have to be considered a blow to WSDOT officials and lawmakers who support the tolled concept over the original I-405 Master Plan.

The Cambridge study recognizes the simple truth that traffic congestion in the non-tolled lanes must exist (and get worse) in order for the tolled lanes to work.

This means only those who choose to pay the toll will experience free flow travel while the vast majority of everyone else is stuck in traffic.

Worse, the proposed toll lanes would be paid for with existing gas tax revenue originally promised to be used for the anticipated general purpose lane expansion found in the I-405 Master Plan. This means that drivers, who paid the higher gas taxes, would not receive any benefit unless they fork over even more money and pay the toll.

With less revenue and higher traffic congestion, it will be interesting to see how lawmakers respond and if they pull the plug on an express toll corridor and instead implement the original I-405 Master Plan that was approved in 2002.

The I-405 Master Plan  calls for up to two general purpose lanes in each direction and according to the WSDOT includes the following benefits:

  • Accommodating an additional 110,000 trips per day.
  • Reducing time stuck in traffic by more than 13 million hours per year – an average of more than 40 hours a year for each regular user of I-405.
  • Producing travel time savings valued at $569 million a year.
  • Removing chokepoints and weaving traffic movements will improve safety by reducing side and rear collisions.
  • Enhancing freight mobility with better interchanges, travel time savings and updated technologies.
  • Providing economic benefits through construction. Each $1 billion spent on transportation construction generates 47,500 jobs, according to the USDOT.
  • $5.40 returned to the economy in congestion savings for each $1.00 invested in highways , also according to the USDOT.


[Reprinted with permission from the Washington Policy Center blog; featured photo credit: short term effect]