July 2006: Washington Governor Christine Gregoire weighs in with a letter blocking the DOT Secretary from participating in Sound Transit's vote of preference for light rail before impact analysis is complete (pdf copy is here).
"Sound Transit's low capacity passenger railroad scheme should be a wake up call to the region's freight community. State Government owns the I-90 bridge and should be persuaded to prevent the contemplated reduction in cross-lake freight capacity." ---- John Niles, member, Puget Sound Freight Mobility Roundtable, presentation on 3-3-06.
Interstate 90 across Lake Washington between Mercer Island and Seattle is a key east/west corridor for the movement of people and freight. The picture below is taken from the Seattle side looking westward toward Mercer Island.
The Sound Transit Board on July 13, 2006 voted a decision to narrow its mode preference to light rail for high capacity transit on the center roadway of the I-90 floating bridge between Seattle and Mercer Island. This would be accomplished in Sound Transit Phase 2 following implementation of lane expansion in the outer roadway under the R8A plan.
On the same day, Governor Christine Gregoire transmitted a letter to the Sound Transit Board of Directors advising that State Transportation Director Doug MacDonald and a Board Member was not to vote a preference for the transit configuration on the I-90 bridge (pdf copy of this letter). The stated reason is that WSDOT will be a co-lead agency in the preparation of documents that analyze the impacts of a "major operational change on a critical facility of the state highway system." The Governor wrote that "congestion and impact analysis already performed by WSDOT will most likely require further refinement and mitigation analysis in the National Environmental Act (NEPA) process."
The center roadway of the I-90 bridge is now a reversible two lanes of HOV traffic flowing in the peak direction. It provides access to buses, carpools, vanpools, and (by special exception) general traffic destined for Mercer Island. R8A provides additional HOV capacity moving in both directions all day.
R8A is an approved plan (with a Record of Decision) to establish four lanes in place of the existing three on the outer roadways. The additional lane in each direction would be HOV, including buses, carpools, and vanpools. According to the Eastside Transportation Association (ETA), R8A expands vehicle capacity in the AM peak by about 10%, and passenger capacity even more.
Now comes a problem because of Sound Transit's intent, amplified by the interest of many political leaders on both sides of the Lake who think light rail is a necessary, good service to build between Seattle and Bellevue. The I-90 center roadway is the only feasible place to build light rail tracks across Lake Washington.
If Sound Transit succeeds in making the center roadway an exclusive transit guideway for light rail trains, the vehicle capacity of the bridge in AM peak will drop by 20% from its present capacity, and by over 30% from the R8A plan, according to analysis by Jim MacIsaac of the ETA, and a contributing editor at Public Interest Transportation Forum..
This reduction in vehicle capacity should be of specific concern to all citizens interested in regional mobility, especially the freight community, for whom I-90 is the main cross-lake bridge.
A better transit solution lies in establishing the center lanes as two-way HOV lanes with room for carpools and vanpools as well as buses. As shown on page two of the pdf, buses interspersed with other HOVs would maximize capacity. Buses crossing the bridge could follow a variety of routes in Eastside neighborhoods, providing better geographic coverage and superior service to a light rail mainline with stations served by feeder buses.
Another alternative is to leave the center roadway as it is, a reversible two lanes of HOV that can flow in the direction that does the most good for vehicle, people, and freight movement depending on time of day.
The HOV lanes could even be converted to HOT lanes, high occupancy toll lanes, a plan under which any available space between HOVs is monitored with cameras and computers, and allowed to be filled by toll-paying solo-driver cars and light trucks. HOVs still travel for free, and the lane is managed with the level of toll to keep it free flowing.
| Details of the planning of the I-90 transit alignment, including history, was published in two reports included in the Draft Supplemental Environmental Impact Statement for the Regional Transit Long Range Plan, available here |
| APPENDIX N: East King County Subarea High Capacity Transit (HCT) Analysis: Approach to Assessing System-Level Alternatives (1.4 megabyte PDF) Prepared by Parsons Brinckerhoff Quade & Douglas, Inc., November 30, 2004 |
| APPENDIX O: Technical Report on Future High Capacity Transit Development Along the Seattle CBD to East King County via I-90/Bellevue Corridor (2.9 megabyte PDF) Prepared by Parsons Brinckerhoff Quade & Douglas, Inc., April 2004 |
Of particular concern is this observation: If light rail tracks were to be placed in the center roadway and the trains operated as planned, there would be five miles of empty track between rush hour trains. See page 2 of the available pdf here. Drivers of cars and buses stuck in traffic on the outer roadway would look over at the tracks and see empty space most of the time. In occasional off-peak congestion, drivers would also see empty space on trains that are even farther apart than five miles.
In the better solution, a bus every 50 seconds on an HOV or HOT configuration would provide superior passenger carrying capacity, and provide space in between buses for other kinds of HOVs that would not need to use the outer roadways.
The I-90 bridge is owned by State of Washington. Sound Transit taking over the center lanes of this bridge with its contemplated low capacity railroad scheme requires approval by State Government. In her letter of July 13, 2006 to the Sound Transit Board, the Governor emphasized that State of Washington is a decision-maker on the transit configuration in I-90 corridor as well as Sound Transit. While Sound Transit has now voted to move forward with planning for light rail construction with no other options on the table, the Governor expressed "no preference with respect to mode choice."
Federal approval will also be required, since this segment of I-90 is part of The Dwight D. Eisenhower National System of Interstate and Defense Highways.
Citizens interested in maintaining the I-90 bridge in a configuration with the greatest vehicle capacity and people-moving capacity should immediately make their views known to the Secretary of Transportation, the Governor, and their state legislators.
[Graphics on this page are from Washington State Department of Transportation.]
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Last modified: October 21, 2008