ST3 Perpetuates Sound Transit's Prop 1 I-5 Fiasco

The previous post opined how Sound Transit’s ST3 plans for the east side exemplified their competence.  This post details how their ST3 plans for light rail to Everett are, at least from a cost/benefit approach, even worse. 

Sound Transit’s purported ST3 plans for a second tunnel and set of light rail tracks to Everett reflect a valid concern for the lack of capacity of their Central Link extension.  The current tunnel limits Central Link to one 4-car train every 8 minutes.  While ST claims each 74-seat car can accommodate 200 riders or 12,000 riders per hour in each direction (rphpd) the PSRC concluded a more realistic maximum is an average of 146 riders or 8880 rphpd.

Even the more optimistic number is barely able to meet current peak transit demand of more than 33,000 riders during the peak 3 hour morning and afternoon commutes (per Oct 2014 Seattle Times article). Thus additional high capacity transit (HCT) is needed for the corridor.  The second tunnel could be designed to accommodate up to 10-car trains similar to BART with 2 1/2 times Central Link capacity.  It could be routed directly to Northgate avoiding all the stops to UW and University Link. 

With the second tunnel ST could terminate Central Link at a T/C at the UW light rail station and avoid spending $2.1 billion on a tunnel for their Northgate extension scheduled to begin service in 2021.  That’s what they could have done.  Instead ST has apparently decided to also design the second tunnel to Everett for 4-car trains. 

That conclusion is based on ST presentations asking ST3 inputs from people whether they preferred, “Light rail with 12,000 rphpd or 700 cars per hour on a gridlocked roadway.”   (Needless to say what they answered.)  Again presumably the 12,000 rphpd assumes 4-car trains.  Thus rather than terminating Central Link at UW and boring a second tunnel capable of accommodating 10 light rail cars, ST is going to construct two light rail lines operating 4-car trains to Everett.  (The Associated Builders and Contractors of Western Washington (ABCWW) must love ST).

The reality is neither the Prop 1 nor ST3 light rail extensions to Everett will have any significant affect on I-5 congestion.  Travel times on I-5 HOV lanes between Everett and Seattle have increased to nearly 75 minutes according to a PSRC “Stuck in Traffic: 2015” report; The obvious problem being too many vehicles on the two lanes.

In 2021 when the Northgate extension begins operation, ST will likely use its limited capacity to replace most of the Metro 41 and other I-5 transit bus routes for the Northgate to Seattle portion of the commute.  However, doing so will have no effect on I-5 congestion beyond Northgate and a miniscule effect on the congestion into Seattle because of the reduced number of “vehicles”.

Any rational cost/benefit analysis would quickly conclude it makes no sense to spend more than $2 billion on a Prop 1 Northgate extension to reduce the number of buses into Seattle.  The fact light rail travel times will “likely” increase because of the several intermediate stops along the route into Seattle makes if even less “beneficial”.  Extending Central Link beyond Northgate adds billions to the cost, does nothing to increase transit capacity, or have a significant effect on I-5 congestion. 

The ST3 extension doubles I-5 light rail capacity.  However, it does nothing to increase the number of transit riders with access to light rail.  The fact there are less than 5000 parking spaces in all the P&R lots along the corridor indicates most of the more than 33,000 2014 transit riders live within walking distance of bus routes.  It’s unlikely the “walk-ons” along the routes will increase significantly in the future. 

Thus, the only way to take advantage of the billions spent adding ST3 capacity is to spend a billion more adding the 30,000 parking spaces with bus connections to light rail stations.  Yet ST could achieve the increased 9-12 thousand per hour transit capacity along I-5 without spending the billions on ST3 by routing the 100-120 buses required directly into Seattle rather than to light rail stations. 

The additional buses would have a miniscule effect on HOV lane congestion if one of the two HOV lanes was restricted to buses during peak commute.  The increased bus traffic could be accommodated in Seattle by converting 4^th Ave into a two-way, bus-only, elongated T/C with designated drop-off and pick-up locations on both sides to facilitate egress and access for each route.

With ST3 they’ll still have to add the 30,000 spaces and connecting bus routes.  Rather than spending billions on Central Link extensions ST should begin adding the P&R next year.  Ask all those who commute into Seattle where they would like to leave their car.  I’m sure many would like to do so near where they live rather than near where they work.  Use the results to prioritize adding 5000 parking spaces each year for the next six years.  By 2023, rather than simply moving existing transit commuters to light rail they will have added parking allowing 30,000 more commuters to use transit,  reducing congestion for everyone. 

Rather than let ST3 perpetuate the Prop 1 I-5 fiasco, adding the parking would end the need for ST3 and save billions in the process.