Lowering the Area's INRIX Rating

The February 12^th Seattle Times Traffic Lab article “Seattle-area traffic, sixth most congested among big U.S. cities” is no surprise to the area’s commuters.  Kirkland based INRIX had the Seattle area as 8^th in 2014.  Congestion has increased markedly since then.   The Traffic Lab article opined, “while Seattle has America’s fastest transit growth, Sound Transit needs two decades to finish a voter approved network of high-capacity rail”. 

However a PSRC, May 8^th,  “Stuck in Traffic: 2015 Report” concluded between 2010 and 2013, the number of commuters who used transit increased from 8.6% to 9.8%.  While the 14% increase over 3 years may have been “America’s fastest transit growth”, the more important statistic, the number of commuters who drove alone only dropped from 74.4% to 73.6%.  It’s unlikely those numbers have changed significantly since then. 

The Traffic Lab article warned, “Sound Transit needs two decades to finish a voter approved network of high-capacity rail”.  They continue to fail to recognize Sound Transit’s ST3 “Prop 1 and beyond” light rail extensions routed through the Downtown Seattle Transit Tunnel (DSTT) will do absolutely nothing to increase transit capacity into Seattle. That any riders added by the extensions, at least during peak commute, will simple reduce access for current riders. (A Nov 4^th 2016, Traffic Lab article conceded ST3 funding would not reduce congestion.)   Clearly spending “two decades” waiting for high-capacity rail is not the answer.

The article also reported WSDOT Secretary Roger Millar had earlier concluded “It would take $115 billion, or a $2.20 gas-tax to construct enough highway lanes to assure 60 mph.  Yet neither considered attracting more of the 73% who drove alone with added bus transit capacity on exiting lanes.  A 70-ft articulated bus can accommodate up to 119 sitting and standing riders.  An additional 100 high-capacity buses an hour could accommodate more than 10,000 riders an hour.

Limiting traffic on highway lanes to 2000 vehicles per hour (vph) has long been accepted as a way to maximize vehicle capacity and attain lane velocities of 45 mph.  Routing an additional 100 buses an hour on a freeway lane with HOT fees set to limit total traffic to 2000 vph would add the equivalent of 4 lanes of freeway traveling 45 mph. An additional 100 buses an hour would add 5 more lanes. 

Clearly adding bus routes is the way to reduce the area’s congestion.  There’s no need to spend billions on additional freeway lanes and no reason to expect two decades of spending billions each year on light rail extensions will reduce congestion.  What’s needed is for the WSDOT to increase highway capacity by implementing HOT fees on I-5, 1-90, and I-405  that limit traffic to 2000 vehicles with Sound Transit making 100 or more of them added bus routes.  

Until Sound Transit is “persuaded” to end its decade long failure to increase bus transit capacity the area’s INRIX congestion rating is only going to rise toward the top.