The Area’s Transportation Debacle Continues

The most recent information on the Seattle area’s congestion ranking is a February 5, 2018 INRIX Global Traffic Scorecard ranking Seattle as 9th worst in the country in 2017.  They had Seattle as 10^th in 2016.  The area’s ranking will surely worsen if Sound Transit and WSDOT are allowed to proceed with current plans for dealing with the congestion.

The problem is the Sound Transit Board is far more interested in spending billions constructing a light rail spine than in reducing congestion.  They compound that problem by choosing to route the Prop 1 extensions through the Downtown Seattle Transit Tunnel (DSTT).  Their ST3 extensions spend more billions on fatally flawed extensions.

Meanwhile the WSDOT is more interested in increasing revenue, forcing commuters to pay tolls, rather than in reducing congestion.  Their approach to imposing HOT fees on two I-405 HOV lanes between Lynnwood and Bellevue has increased GP lane congestion between the two cities and failed to meet the 45 mph “requirement” during peak commute on HOT lanes.  Their plans for HOT lanes between Bellevue and Renton will further increase GP congestion and again fail to achieve the “required” 45 mph for much of the peak commute.  

Reducing traffic congestion requires either increasing the number of commuting lanes or increasing the capacity of existing lanes.  Sound Transit has refused to increase the capacity of existing lanes by increasing  parking with access to bus routes into the city.  Instead their light rail spine adds commuting lanes along the I-5 corridor.   However, a 2004 PSRC report concluded their decision to route it through the DSTT limited capacity to 8880 riders per hour (rph) in each direction. The billions spent on Prop 1 and beyond light rail extensions do nothing to increase that capacity. 

Roadway capacity studies have shown that limiting a highway lane to 2000 vehicles per hour (vpr) will allow it to average 45 mph.   Thus, the light rail spine’s 8880 rph “could” add ~ 4.5 highway lanes of “single occupancy vehicles (SOV) capacity at 45 mph.  However, there are several problems with using the spine along I-5.

First, the 8880-rph capacity is a fraction of what’s required to accommodate the number of riders needed to reduce congestion.  Second, using that capacity to reduce congestion along I-5 from Everett will eliminate access to those currently using University Link and projected to use the Northgate extension.   Third, Sound Transit neglects to add the parking needed for light rail access, planning instead to use it to replace current bus routes, apparently not recognizing reducing the number of buses on I-5 HOV lanes does nothing to reduce GP lane congestion.

The light rail extensions south of Seattle and across I-90 Bridge are even more “problematic”.   Each, having only half the DSTT capacity, will do little to reduce congestion.  Again, commuters added by the extensions beyond SeaTac will displace current riders.  The East Link extension across I-90 Bridge, rather than adding  “traffic lanes,” replaces the two center roadway lanes.  They were allowed to do so by convincing a federal judge the center roadway lanes weren’t needed for vehicles, ignoring a FHWA Record of Decisions stipulating they were still required.  The inevitable result will be future gridlock for cross-lake vehicles.  Again, Sound Transit fails to add the parking needed for light rail access, planning to use East Link capacity to replace cross-lake buses with little effect on congestion.

Clearly, the billions Sound Transit plans to spend on the light rail spine fails to reduce I-5 congestion and increases I-90 bridge congestion.  Even more “problematic”, the spine operating costs will either necessitate “substantial” fare increases or a large increase in subsidies to cover the fare box shortfall.   

Sound Transit budgets light rail cars cost ~$25 per mile to operate or ~$100 per mile for 4-car trains.  Their extensions to Everett add 33.6 miles to the 4.3 mile University Link or 67 miles to the round trip.   Thus each round trip to Everett adds ~ $6700 to Sound Transits operating costs.   Assuming 180 round trips a day (4 minute headways between trains for 8 hours and 8 minutes for 8 hours) the Everett round trips will add $1.2 million to weekday operating costs.  Assuming half those frequencies on weekends, the Everett extension adds $375 million to Sound Transits annual operating costs.  The extensions to Tacoma and Redmond while shorter will likely add $150-200 million.  Clearly light rail spine operating costs will dwarf fare-box revenue.

Meanwhile, the WSDOT demonstrates their quest for increased revenue with plans to implement 2 HOT lanes along I-405 from Lynnwood to Renton.   They refuse to recognize the $484 million 2-year “pilot program” between Lynnwood and Bellevue increased GP lane congestion and failed to provide the 45 mph on the HOT lanes during 90% of the peak commute.  (Despite the fact they defined peak commute as beginning at 5:00 A.M).

The problem is the WSDOT decision to restrict GP use to 3 of the 5 lanes between Bothell and Bellevue increases congestion to where the number of commuters willing to pay the maximum allowable $10 tolls exceeds the 2000 vph needed to maintain the 45 mph. They clearly don’t acknowledge the problem since they’re planning to spend $1.2 billion implementing 2 HOT lanes between Lynnwood and Bothell, and Bellevue and Renton, restricting GP use to 2 of the 4 lanes.

Limiting GP use to only 2 lanes will “likely” force even more commuters to use HOT lanes, further reducing their velocities.  Between Bothell and Bellevue, the WSDOT is already considering raising fees on the two HOT lanes to meet the 45 mph for 90% of the peak commute. They’ll surely need to do so with GP traffic reduced to 2 lanes.

A far better way would be to raise the fees on one of the HOT lanes between Lynnwood and Renton to whatever it takes to maintain 45 mph for 100% of the commute and allow GP use of 2^nd HOT lane.  HOT users would be assured of 45 mph and GP congestion would be reduced with the added lane.    (Unlimited-fee HOT could also be implemented on an I-5 HOV lane assuring 45 mph for those willing to pay for that route into the city.) 

Equally important, single HOT lanes on both I-5 and I-405 could assure 45 mph for bus routes, making public transit more attractive for both routes.   Unfortunately, Sound Transit has shown no interest in adding the parking or bus routes needed to take advantage of the unlimited fee HOT lane reliability.

The bottom line is Sound Transit is planning to spend billions on Prop 1 and beyond light rail extensions that will do nothing to reduce I-5 congestion, will increase I-90 congestion and require a huge subsidy to operate.  The WSDOT plans for implementing 2 HOT lanes on I-405 will either end up with a failure to achieve the 45 mph during the peak commute or a huge increase in fees to limit HOT use.  Both will increase GP lane congestion.

The Seattle area’s ranking will only get worse as the debacle continues.