Public Interest Transportation Forum -- http://www.bettertransport.info/pitf

Sound Transit EIS Document Predicts
Link Light Rail to Northgate Won't
Change Seattle Rush Hour Traffic in 2010

by Jim MacIsaac and John Niles

Many hopes and claims have been made as to what the light rail system planned by Sound Transit will do for Seattle. The most significant claim or implication is that it will reduce or at least stem the growth of traffic congestion. But those making this claim are leading with their hearts and hopes, not with the official government forecasts in the November 1999 Environmental Impact Statement (EIS) for the project. After several millions of dollars in studies and travel modeling, the EIS on page 3-5 (Section 3.1.2.2) states:

"The Transportation Technical Report provides further information on traffic volumes across screenlines. In most cases, the traffic volumes across screenlines with light rail alternatives are within one percent of the No-build volumes. This small difference is generally within the reliability levels of regional models. Therefore, based upon traffic forecasts, the light rail system will not result in a significant difference in regional traffic volumes, but it will provide needed additional travel capacity. Peak hour volumes for the No-build and light rail alternatives are also expected to be similar across all screenlines."

What the EIS is telling us is that there will be little effect on traffic volumes within the rail corridor, whether we implement the rail plan or do nothing (No-build). To illustrate this statement graphically, we have copied Figure 5.2-1 from the referenced Transportation Technical Report (page 96) from Sound Transit and presented it below on this page.

The graphic is a simplified map of Seattle showing the major highways and the several Link light rail routes studied from S.200th Street to the Northgate shopping center area. It shows three drawn-in screenlines, each an artificial straight line that crosses several main highways or arterials that parallel the planned tracks of light rail. City of Seattle "concurrency guidelines" require analysis of future traffic volumes crossing these screenlines with and without a planned project. The estimates of total vehicles (cars, trucks and buses) crossing each screenline with "Light Rail" and without the rail project ("No Build") during the PM Peak Hour (late afternoon commuting time) of the day by year 2010 are shown to the right of each screenline location. The range of the estimates shown with "Light Rail" represent the range of difference in findings for the several alternative rail route alignments. All estimates reflect completion of the train line to Northgate.

Result: The calculated future traffic volumes across each of the three screenlines with and without Link light rail are practically the same. For example, the top screenline at the Lake Washington Ship Canal shows an estimate of 45,789 vehicles crossing this screenline during the PM peak hour in 2010 under the "No Build" scenario. Full implementation of the Link Light Rail plan from S.200th Street to Northgate would result in a reduction of between 34 and 55 vehicle trips, or a traffic reduction of 0.1% (0.00098). Traffic reductions crossing the screenline South of I-90 are estimated between 0.3% and 0.7%. At the screenline North of I-5/SR518 the estimates show that there could even be a very slight increase in traffic after building light rail.

There are a number of other tables in the EIS documents that evaluate vehicle-miles of travel, vehicle-hours of travel, effect on air quality and a number of other global environmental factors. They all result in findings of a fraction of 1% difference between the Build options and the No Build alternative.

Rail Screenlines.jpg (448263 bytes)

Bottom line result from the official analysis:  no environmental difference between building the proposed Link Light Rail and doing nothing.

Obviously if the Light Rail project is built, some people will ride it. In fact many existing bus riders originating north of Northgate and south of S.200th Street will be forced to transfer to rail to complete their trips to destinations along the rail line -- some express bus routes will be truncated at these outer stations. Some riders originating within the rail corridor will also lose direct bus services to downtown Seattle and instead be transported laterally and forced to transfer to rail.

What the EIS studies are telling us -- if we care to listen -- is that the rail line will predominantly serve pre-existing bus transit riders. It will do nothing to address traffic congestion and the choice to travel by private auto and carpools.

Where do the editors of the Public Interest Transportation Forum stand on building light rail?

The calculations do not surprise us. Not enough people will ride the Seattle light rail train to make any difference in traffic. This has already been shown by light rail in other US western cities. The measured contribution of light rail to the level of traffic is very minor. Nobody can afford to build rail systems with tracks to enough of the places where people need to go. Most people will need to travel by car or ride the bus to get from their home to a Link light rail station. This requirement limits the appeal of the system.

And what about building it anyway, in the words of the EIS, to "provide needed additional travel capacity"?

Simply building more "seats" in a corridor does not mean they will be used. We already have three or more empty seats in most vehicles on our road system. Any program to utilize better those already available empty seats would be a much more cost-effective solution than investing in a rail project that appears headed toward more damage to the neighborhoods through which it passes than it will provide benefit.

It is simply wasteful to spend billions of dollars to replace portions of what is considered one of the best bus transit systems in the country. Our answer on expensive "additional travel capacity" is negative. Don't build the Link light rail!  Even before we turn the first spade of dirt it is already looking like "WPPSS on Wheels."

Sound Transit and supporters would tell you that in the long-run future, 10, 20, or 30 years beyond the year 2010, the high capacity of the new Link light rail will eventually be used.

We would call that judgment a high-stakes gamble with our limited transportation tax dollars.  There are less risky, less expensive, more effective ways to build a transportation system for the future, many of which are listed here in a paper by Nelson and Shakow. And here in a paper from Citizens for Mobility. And even here in a list of what we have earlier analyzed to be cost-effective elements in the 1996 Sound Transit Plan that could be expanded.

Light rail in Seattle should be killed now, and the money for it should be reprogrammed to solutions that will work.

Comments or Questions?  Email niles@globaltelematics.com

Citizens for Mobility: Position paper and e-mail address

John Niles is co-editor and Jim MacIsaac, P.E., is contributing editor, Public Interest Transportation Forum.

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Last updated February 07, 2011