New Study: Light Rail On I-90 Bridge Will Increase Traffic Jams

Seattle - The Center for Transportation Policy at Washington Policy Center (WPC), Washington's premier public policy research and education organization, released the fourth installment of its ongoing coverage of the ST2/RTID ballot measure appearing this November.

The new Policy Note Part IV: Light Rail and Interstate 90: Sound Transit's proposal to place light rail across I-90 will increase traffic congestion, analyzes the affects of one of the more controversial projects in Sound Transit's proposed second phase (ST2). This project plans to reconfigure the center lanes of I-90 to accommodate up to 19 miles of light rail between Seattle and Bellevue.

Michael Ennis, director of the Center for Transportation Policy and author of the Policy Note says, "Our research shows that this project would increase delay and lead to millions of dollars of additional costs to the commercial trucking industry; and it appears to violate the federal government's policy of reducing traffic congestion." Ennis concludes that, "Our study concludes that under Sound Transit's plan, consumers, taxpayers and drivers would be better off if policymakers did nothing on I-90."�

Here are the key findings of the report.

• Sound Transit's plan to place light rail on Interstate 90 will reduce overall vehicle capacity on the bridge by 15% during the morning peak commute and 8% during the afternoon.
• Light rail will increase vehicle delay on the bridge by 27% during the morning peak drive and 24% during the afternoon peak.
• ST2 will cause average westbound vehicle speeds to fall 21% during the morning peak commute and eastbound drivers in the afternoon would see a 17% decrease.
• Freight vehicles would suffer the most.  During the morning peak drive, the number of freight trucks able to cross into Seattle would drop 24%.  Leaving Seattle during the afternoon peak drive, trucks would see a 19% reduction in capacity.
• The light rail option will cost the commercial trucking industry about $7.5 million annually simply to cross the I-90 bridge during peak commute times.  This is 54% more than if policymakers did nothing on I-90.
• The light rail plan on I-90 also appears to violate the federal government's National Strategy to Reduce Congestion.

The previous three installments in this series include: Part I: The Cost of Sound Transit, Part II: Your Transportation Tax Burden, and Part III: Cost Exceeds Benefits in Sound Transit’s Light Rail Expansion.

Michael Ennis is available for comment by contacting Lyndsey Hartje at lhartje@washingtonpolicy.org or call 206-937-9691.