WSDOT Toll Report Belies I-405 “Clogging”

The February 13^th Traffic Lab headline "Washington’s $15 Tolls Hope to Reduce Traffic, Increase Revenue” prompted a review of the WSDOT Toll Report. The 2023 Fiscal Year Report for “Express toll lanes” included the following for “I-405 Express Toll Lanes vs General Purpose Lane Speeds FY 2023”.

 The southbound morning peak period sees the lowest performance in the single-lane section between Lynnwood and Bothell with the tolled lane averaging speeds of 46 mph-though still notably higher average speeds than the general-purpose lanes in the area.  The tolled lanes in all other sections achieve average speeds of 50 mph or greater during the peak period.

 

It’s followed by “Express Toll Lane Speeds are Faster Than General Purpose Lane Speeds

 

Northbound Bothell to Lynnwood = 12 mph faster

Southbound Lynnwood to Bothell = 15 mph faster

Northbound Bellevue to Bothell = 23 mph faster

Southbound Bothell to Bellevue = 9 mph faster.

 

The goal of most state transportation systems HOT fees is to maximize HOV lane capacity by setting fees that result in 2000 vehicles per hour and 45 mph velocity.  That doing so avoids the problem when more than 2000 carpoolers per hour slow the HOV lane during peak commute and fewer than 2000 carpoolers waste capacity that could be used to reduce general purpose lane congestion.  Thus, most transportation commissions would consider the HOT fees on the Lynnwood-to-Bothell just about right and consider reducing Bothell-to-Bellevue fees to increase the HOV lane capacity or eliminate HOT on one of the two lanes.  

 

The WSDOT HOT approach is more about increasing HOV lane velocity (and revenue) than increasing capacity that reduces general-purpose lane congestion.  Calling the Lynnwood-to-Bothell section's 46 mph the “lowest performance” section and increasing fees to on lanes on sections that already “average speeds of 50 mph or greater during the peak period”. 

It’s especially egregious they’re wasting capacity on two HOV lanes.  If they wanted to increase HOV lane velocity and waste that capacity they should do so on one HOV lane.  Those unwilling to pay the fees on the return Bellevue-to-Bothell would no longer be forced to travel 23 mph slower, even slower with increased congestion from  $15 tolls.

Instead, the February 13^th Traffic Lab article included the following excerpts:

 

State law requires express toll lanes to flow at 45 mph during 90 percent of commute hours. The success rate was only 87 percent on I-405 and 63 percent on Highway 167 during early 2023, the Washington State Transportation Commission reported.

As of September, midweek data showed southbound Highway 167 hitting its $9 ceiling in 74 percent of peak afternoon hours, and I-405 reached its $10 max in 40 percent of southbound morning peak hours, the commission reported.

"The problem is you pay $10, and you still get stuck in congestion," said Mark Hallenbeck, retired director of the Washington State Transportation Center, at the University of Washington.

The bottom line is one can only surmise the ones raising the HOT fees, the Washington State Transportation Commission, had not bothered to read the WSDOT 2023 Year Toll Revenue Report. The report was surely available when the toll increase was considered.  It’s particularly “unfortunate” the Seattle Times Traffic Lab did not “dig into” the actual report.  Thus, the March 1^st $5.00 increase just adds to the debacle of WSDOT imposing HOT on two HOV lanes.