More On ST/WSDOT Stopping I-90 Buses

The Jan 21^st ST/WSDOT East Link presentation to the Mercer City council explaining their plans to terminate all I-90 buses at either the South Bellevue or Mercer Island light rail stations was an “eye opener”.   I had heard about plans to terminate cross-lake buses, but thought they involved only routes west of I-90 near the light rail route.  Thus, my response to the chart showing all I-90 bus routes ending at either of the two stations was one of “disbelief” rather than “surprise”.

I simply didn’t believe anyone could be so stupid as to close off the I-90 center roadway in 2016 and spend the next seven years and $2.8 billion constructing a light rail system to “replace” I-90 buses.  I had always assumed the majority of the buses would be diverted to the 4^th lane ST had added to the outer roadway.   While I had concerns about the resulting congestion on the outer roadway, the idea ST would terminate all the bus routes rather than divert them never occurred to me.

It’s doubtful even ST/WSDOT still believes their EIS claim light rail has capacity for up to “24,000 riders per hour (rph)” that could “increase person-moving capacity across Lake Washington on I-90 by up to 60 percent”.  Their EIS asserted they had based the decision for selecting light rail on a 2004 the Puget Sound Regional Council (PSRC) study document “Central Puget Sound Regional High Capacity Transit Corridor Assessment”.   It stipulated a minimum of 4-minute headways between trains with each 74-seat car carrying a maximum of 148 riders with 4440 or 8880 rph for the 2 or 4-car trains respectively. 

The combined capacity for the two tracks through the Seattle tunnel was 8880 rph and 17760 rph for the two train configurations with presumably half  that capacity (4440 rph or 8880 rph) allocated to East Link.   Its unlikely ST would use 4-car trains for East Link since light-rail-operating costs ($25 per mile per car) make the Lynnwood portion of the route prohibitively expensive.

Each 26-mile round trip to Lynnwood would cost $2600 or nearly $20,000 per hour of operation for 4-car East Link trains every 8 minutes. (This cost is probably the reason their recent tests confirming I-90 Bridge can support light rail only used 2-car trains.)  The total Lynnwood extension costs would presumably also include the cost for 2-car Central Link trains every 8 minutes.  (The reality is light rail operating costs, even if both routes had only 2-car trains, dwarfs potential fare box revenue)

The bottom line is the likely combined inbound and outbound cross-lake capacity for East LInk is 4440 rph, a fraction of the 24,000 rph Sound Transit promised.  It’s “unlikely” light rail trains with 2220 rph capacity into Seattle will be sufficient for bus commuters in 2023, let alone the 60% increase in “person moving capacity” they’re projecting

 

The end result will likely be ST would allow many of the bus routes to continue on the bridge outer roadway into Seattle increasing congestion on the bridge.   It's also likely large numbers of bus commuters forced to transfer to light rail will opt out of public transit altogether. 

All of this “insanity” could be avoided.  ST could expedite the 4^th lane additions to the outer roadways and initiate two-way bus service on the center roadway for a fraction of the $2.8 billion they plan to spend on East Link.  The improved bus service could be operating in 2015 with cross-lake capacity for up to 1000 buses per hour in each direction.  Every eastside P&R along with the Bellevue T/C could have non-stop routes into Seattle. 

Commuters attracted by the ability to leave their cars near where they live would reduce congestion throughout the area.  The fact it avoids the need to close the bridge center roadway, the devastation along the route into Bellevue, and the financial "black hole" from operating twice as many trains to Lynnwood as the east side makes it even more imperative.  Again, it’s way past time for those with the authority to end this debacle to do so.