The Unlikely I-5 "Livewire Event Solution"

 The previous post opined the Oct 29^th Seattle Times “Livewire Event” sponsored by Sound Transit was “unlikely” to recognize the “Solution” to the I-90 corridor congestion problem was to move the non-transit HOV to 4^th lanes on the outer roadway, initiate two-way bus only lanes on the center roadway, and use the East Link funds to add thousands of parking spaces throughout the east side and bus routes to serve them.

This post opines the forum is also “unlikely” to come up with “Solutions” to the congestion along I-5.  A May 8^th, PSRC presentation to the Eastside Transportation Partnership (ETP) “Stuck in Traffic: 2015 Report” quantifies the congestion along that corridor.  It includes a chart (Page 20) showing I-5 HOV travel times in 2014 between Everett and Seattle had increased to ~75 minutes in the morning, and ~68 minutes in the afternoon.   Comparable times between Federal Way and Seattle were ~52 minutes and 48 minutes.

No one in their right mind would conclude that the delays in the HOV lanes are due to too many buses. Yet ST apparently believes that fantasy.   Why else would they plan to spend billions over the next 8 years on Central Link extensions to stations where the only ones with access will be to those who previously rode buses. 

The PSRC concluded in a 2004 report “Central Puget Sound Regional High Capacity Transit Corridor Assessment” that the Seattle tunnel limited light rail capacity to 8880 riders per hour (rph) in each direction.  When the Central Link Northgate extension begins operation in 2021, the 8880 rph will far exceed the number if those who previously rode Metro from the T/C there into Seattle.  ST will presumably route other buses to Northgate rather than into Seattle to make use of Central Link capacity.  (They plan to terminate all the cross-lake bus routes on I-90 at South Bellevue or Mercer Island light rail stations.) However even if they manage to use the entire 8880 capacity, it will only reduce the number of buses between Northgate and Seattle by about 100 buses per hour. 

A freeway lane can accommodate up to 5000 vehicles per hour.  A hundred-bus-per-hour reduction would have a miniscule impact on the HOV lanes congestion.  Conversely if they chose to add 100 buses per hour they would provide the capacity to reduce the +2 HOV traffic by 5000 vehicles per hour dramatically reducing HOV lane congestion.  If each parking space in the suburbs cost $20,000 they could add 15,000 parking spaces with the $300 million ST will spend on the Northgate extension next year alone.  The added parking could not only accommodate the HOV commuters but more single drivers, also with a minimal number of added buses.  And they could begin doing so in 2017.

Rather than use the Northgate and beyond extensions to attract light rail riders, ST should override UW objections and insist on a T/C near the stadium station. It could provide thousands of 520 transit riders from both sides of the lake with an interface between cross-lake BRT and Central Link light rail, taking advantage of light rail capacity without the expense of the light rail extensions.

The increased bus frequency could be facilitated in Seattle by converting 4th Avenue to a two-way bus-only lane configuration. Buses would use one side to drop off riders and the other to pick up riders depending on which direction they came from.  Doing so would allow each route to have one or two dedicated egress and access locations making maximum use of the roadway and further reducing transit times.

Again, it’s “unlikely” the Seattle Times Livewire Forum will result in these “Solutions”