Toll plan for Puget Sound WA floating bridge moves forward

Plans to reimpose tolls on at least one of two major Seattle area bridges are moving forward with political and public support. Tolls would begin in 2010 on the existing WA520 over Lake Washington to provide funds for major reconstruction and some extra lanes, and for traffic management to allow freer flow and improved speeds. The tolls would continue when the new and improved bridge opened in around 2016.

WA520 is known locally as the '520 bridge' after state route 520 and its formal name is Evergreen Point Bridge. The existing bridge is nearly 50 years old, too narrow, and rated vulnerable to destruction by windstorms and earthquakes.

There is majority public support for the toll projects - 59% for 30% against tolling WA520 bridge and 65% for tolling both WA520 and the parallel I-90 bridge - after a study of alternative scenarios and extended public outreach. WA520 and I-90 are the major east-west routes in the greater Seattle or Puget Sound metro area.

Project cost for the two bridges and approach corridors is in the region of $3.7b to $3.9b. The project would widen and rebuild the WA520 floating bridge and some 10km (6 miles) of the corridor on either side, and improve the I-90 bridge.

Washington state legislators set a funding target for tolls of $1500m to $2000m to fund the improvements with the remainder of funding from federal, state and local tax sources. Only one scenario tolling WA520 alone gets into the target range and only barely. All the two bridge tolling scenarios raise the required money. The highest would raise around $2500m.

Variable tolls

Flat rate tolls are estimated to improve average peakhour speeds from about 20mph (32km/hr) to 30mph (48km/hr) and variable tolls would raise them to 38mph (61km/hr).

The plans are to build a new WA520 bridge with 3x2 lanes in place of the existing 2x2 lane bridge, while the I-90 bridge would be improved but have no capacity added. Major additions would be made to bus transit in both corridors.

Average daily traffic is 115k on the WA520 and 150k on I-90.

A report by IBI Group suggests that 2 million transponders will eventually be needed to support open road tolling on the two extra bridges plus the existing toll facilities in the area - Tacoma Narrows Bridge and WA167 HOT Lanes.

The IBI report says that 5.9GHz VII is the best technology for open road tolling followed by ASTMv6 TDMA which is rated 'better' than the other alternatives. IAG, super eGo and Calif T21 are rated only 'acceptable.' GPS is described as insufficiently accurate for needed lane discrimination in an urban environment.

Under the tolling proposals carpoolers will get discounted tolls so toll equipment must allow drivers to 'declare' their occupancy via a switch on the transponder - requiring availability of hardcased as well as sticker tags.

Tacoma Narrows tolls

On the Tacoma Narrows Bridge after tolling began in 2007 use of transponders has risen to over 70% overall with 85% in peakhours. This is highway speed open road tolling.  Traffic is about 80k/day and one-way tolls number an average 40k. Tolling uses dual mode readers from TransCore set up to read Super eGo sticker tags on cars and ASTMv6 truck transponders, a Raytheon TDMA design.

However on the WA520 and I-90 bridges there would be no cash toll option as on Tacoma Narrows Bridge.

Bill to authorize WA520 tolls Jan 1 2010

Feb 16 saw introduction of a bill (HB2211) into the Washington state legislature authorizing a toll of up to $3.25 each direction on the WA520 bridge starting Jan 1 2010. Legislators haven't accepted tolls on the I-90 bridge.

see http://build520.org

TOLLROADSnews 2009-03-11