Traffic Lab Abides WSDOT I-405 HOT Debacle

A previous post opined that the Seattle Times Traffic Lab’s “exploring how billions of dollars in public money are spent” has abetted Sound Transit’ spending $12.5B implementing a Ballard to Sodo light rail extension. A transit project whose construction will disrupt downtown Seattle boring a 2^nd tunnel and closing vital roadways in South Lake Union. All for a light rail transit system that will have far less access than current bus routes to far more convenient destinations. 

This post details the Traffic Lab is also abiding a more immediate I-405 debacle. The WSDOT raised HOT fees and is spending hundreds of millions adding lanes between Bellevue and Renton as part of their plan to impose increased HOT fees on two I-405 HOV lanes between Lynnwood and Burien.    

WSDOT recently increased the HOT maximum fares to $15.00, purportedly to reduce HOV lane clogging.   However, the 2023 Fiscal Year Report for “I-405 Express Toll Lanes vs General Purpose Lane Speeds FY 2023” concluded the HOT lanes achieved 50 mph or greater during the peak period. That prior to the fare increase southbound and northbound Bothell-to-Bellevue HOT lanes were 9 mph and 23 mph faster than the GP lanes. 

By comparison recent WSDOT Travel Times on June 11^th 7:50 indicated the $15 HOT fees had increases HOV lane velocity to 64.5 mph.   However, the higher fees reduced the number of GP lane drivers willing to pay.  The added vehicles increased traffic and travel time to where average velocity was 32.3 mph or 30.2 mph slower than on HOV lanes. The HOV 5:05 pm return route velocity with increased fee was 56.5 mph, the average GP velocity, 20.2 mph, 36.3 mph slower.  

Clearly the WSDOT’s increasing the fares did more to penalize those not paying the fares than benefit those that did.  Yet the Traffic Lab continues to abide the WSDOT I-405 imposing HOT fees that are more about increasing revenue than reducing travel time.  Especially when having two HOT lanes wastes capacity that could be used to reduce travel time on GP lanes.

Even more blatant, they continue to abide WSDOT plans to impose HOT fees on both the existing HOV lane and the new lane between Bellevue and Renton. The recent 7:50 am northbound route averaged 16.8 mph on the two GP lanes and 27.3 mph on HOV lane.  The 5:05 pm southbound route average was 19.6 mph on two GP lanes and 30.3 mph on HOV lane.  Clearly both need improvement from additional lane.

Yet the WSDOT plans to impose HOT on HOV lane will force carpoolers not willing to pay the HOT fees to use one of the two GP lanes. That the resulting increased GP lane traffic and slower speeds will increase the incentive to pay the HOT fees and more funds for WSDOT.  Having a second HOT lane will allow those paying the fees will result in speeds limited by 60 mph limits rather than traffic.  However the loss of the GP lane will exacerbate the penalty for those not paying the fees.

The bottom line is imposing HOT on a second lane does little to reduce HOV travel time. However, the loss of a lane and former carpoolers adds traffic to GP lanes that exacerbates the penalty for those not willing to pay.  That imposing HOT on one HOV lane can benefit, not only those paying the fees, those not paying can benefit because HOT fees allow more than just carpoolers to use HOV lane, reducing GP lane congestion and travel time.  

The Seattle Times Traffic Lab needs to recognize the benefits of single HOT lane rather than abiding WSDOT I-405 two lanes.