Legislators Should Reject WSDOT I-405 2-HOT Lane FONSI

(As always I referred this post to the House and Senate Transportation committee members)

The April 12^th notice by the WSDOT and FHWA “Finding of No Significant Impact” (FONSI) for the I-405, Tukwila to I-90 Vicinity Express Toll Lanes Project shows neither understands the devastating impact of WSDOT plans for 2 HOT lanes on I-405 travel times.  The FONSI is a sales pitch for legislative approval for 2 HOT lanes on I-405 that ignores the reality of HOT benefits and should be rejected.

The “conventional” benefit from HOT is they increase HOV lane velocity by raising tolls to limit traffic; typically 2000 vehicles per hour (vph) will assure 45 mph velocities.  HOT fees avoid the HOV lane slowdown when more the 2000 carpoolers an hour use the lane. HOT also benefits public transit because the assured 45 mph velocity enhances bus ridership.  However using HOT fees to reduce traffic on HOV lanes increases traffic and congestion on GP lanes.

The WSDOT bases its plans for 2 HOT lanes on the presumption HOT fees increase HOV lane capacity.  The project director claims, “toll lanes often carry 35 percent more cars per hour than general lanes. That’s because rising prices prevent toll lanes from being clogged.  Express toll lanes flow better while GP lanes will be clogged from the start”. 

The FONSI uses this rationale to make the following claims for I-405 commuter benefits from 2 HOT lanes.

• Provides a reliable trip choice for I-405 users
• Increases vehicle capacity and person throughput
• Improves access for I-405 users
• Improves reliability for transit
• Reduces project-wide congestion

The FONSI “substantiates” these claims with the following excerpts:

Because this project adds a new lane in each direction, all travel lanes on I-405 would operate with faster, more reliable trips and would accommodate more vehicles than without the project.

With the project, average travel times during the morning and afternoon peak periods would improve in both the general purpose and express toll lanes.

Adding a new lane will increase I-405 capacity.  However using the new lane for HOT limits capacity and implementing HOT on the existing HOV lane will force 2-person carpools to use GP lanes.   It currently takes up to 90 minutes during peak commute on the GP lane and up to 50 minutes on the HOV lane for the 23-mile commute between Federal Way to Bellevue.  Using HOT to reduce HOV traffic to what’s required to achieve 45 mph will add to GP traffic and further increase travel time.

The increased GP lane congestion will convince more commuters to pay for HOT, increasing HOV lane congestion and travel time.  Travel time between Lynnwood and Bellevue exemplify the problem with current HOT fees with HOV travel times  up to 30 minutes and GP lanes taking nearly twice as long.  Implementing HOT on 2 of 4 lanes between Bellevue and Renton rather than on 2 of 5 lanes will likely exacerbate the problem. 

The bottom line is with 2 HOT lanes on I-405 the WSDOT has to choose between raising HOT fees to reduce HOV traffic, exacerbating GP lane congestion or accepting longer commute times for those willing to pay with less increase in GP congestion. However, the slower HOV lanes also ends one of the WSDOT's HOT purported benefits:

The project is essential to provide speed for Sound Transit’s new I-405 Bus Rapid Transit line from Lynnwood to Burien, scheduled to open in 2024.

The WSDOT could reduce GP travel times and assure 45 mph HOV lane velocity by implementing HOV on one lane with fees raised to whatever was required to achieve 45 mph.  Doing so would assure 45 mph for those willing to pay and for BRT routes.  The additional GP lane would reduce congestion for those unwilling or unable to pay and lower the fees for those willing to pay.  

The WSDOT proposal for 2 HOT lanes on I-405 is more about raising revenue than for reducing congestion.  They need to be "persuaded" to accept the lower revenue from a single HOT lane.  The legislature should do so by rejecting the FONSI for 2 HOT lanes.