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

How Sound Transit Abused the Planning Process to Promote Light Rail

by Richard C. Harkness, Ph.D

January, 2005

Sound Transit is the regional transit planning agency for the Puget Sound Region of Washington State

This is the short version of an extensive study I performed over the course of six months in 2004. The complete study is available through a link at the bottom of this page.

Sound Transitís Board is increasingly committing the central Puget Sound region to use light rail, as opposed to bus rapid transit (BRT), for the region’s mass transit backbone.  In 1996 voters approved spending $1.8 billion for a 21-mile light rail system. 

In 2001 Sound Transit (ST) admitted their initial cost estimates were wrong and shortened the line to 14 miles, from Westlake Mall in downtown Seattle to the boundary of Tukwila and SeaTac, about two miles by bus north of SeaTac Airport.. However ST still hopes eventually to build over 125 miles of light rail and is taking administrative steps toward doing so.

Sound Transit has continually justified its choice of light rail technology on an alternatives analysis done in 1993 by Sound Transit’s predecessor agency, the Regional Transit Project (RTP).  This particular study compared a 125-mile rapid rail system costing $11.5 billion against an express bus alternative costing $4.7 billion.  I went back to give this study some additional attention it badly needs, since ST is still referring to it as valid a decade after it was issued. 

During the course of that study RTP predicted year 2020 ridership for both the bus and rail alternatives, and then evaluated their capacity to handle the predicted ridership.  In looking at bus system capacity through downtown Seattle, the RTP assumed the existing Downtown Seattle Transit Tunnel -- the bus tunnel under Pine Street and Third Avenue -- could only carry 100 buses per hour in each direction, even though six previous studies had concluded its capacity was significantly higher than that.

At this point the RTP had a choice. Either it could verify that 100 buses per hour was the correct value, and if so, apply one of the remedies that staff had already identified.  Or it could penalize the bus alternative.  It chose the latter course of action, and then proceeded to reduce predicted ridership for the bus alternative. RTP claimed it did not have enough capacity to meet the region’s needs. In addition, because the bus alternative now had lower ridership, the RTA also down-rated it on all other ridership related benefits, such as its ability to improve mobility and support land use goals.

In short, the RTP compared a robust, grade-separated rapid rail alternative against a deliberately hobbled bus alternative and used the results to rule out bus technology for the region’s main transit spine along I-5.  In its Draft Long-Range Plan released December 2004, Sound Transit still relies on that corrupted 1993 alternatives analysis to justify proceeding with light rail.

Fortunately, I was able to take steps to estimate what would have happened if RTP had elected to remedy the alleged capacity problem rather than penalize the bus alternative.  To compare apples to apples it is necessary to have two alternatives that are either equal in benefit or equal in cost.  I elected to modify the bus alternative so it would attract the same ridership as the rail alternative, and then compare costs. 

The first step was to remove the alleged capacity bottleneck using -- to be conservative -- the most expensive remedy identified by RTP staff, namely, building a second parallel bus tunnel costing $600 million. This allowed the bus alternative to carry its originally predicted ridership, which was 93% of what the rail system was predicted to carry. To get that last 7% I used an RTP estimate for the cost of attracting extra riders.

The result is that a modified bus alternative would be $400 million per year less expensive (in 1991 dollars) than the rapid rail system chosen by RTP.  This is the picture that the RTP could have produced using information available at that time.  However, RTP chose not to do so because officials wanted rail to win. 

Today there is every indication Sound Transit’s Board wants to build at least 125 miles of light rail, some of which, unlike rapid rail, is to be at-grade with places for cars and trucks to cross the tracks.  There has never been an apples-to-apples comparison between bus rapid transit (BRT) and any of the different-sized light rail networks that Sound Transit is contemplating, much less a 125-mile system. 

However; it is possible to make an approximation.

First, we can assume that 125 miles of Link light rail would attract as many riders as 125 miles of rapid rail.  Clearly, it would not do this, because Link is slower, but this is the conservative approach.  Then we have  to estimate the cost of a 125-mile version of Link and compare that with an all-bus or BRT alternative. The 1993 cost comparison can be reused, but only after adjusting it for the facts that Sound Transit’s early rail cost estimates were 44% too low and that many of the HOV lanes needed for the bus alternative have now been completed.

The results show that a 125-mile light rail system would cost about $900 million per year more (in 2002 dollars) than a comparable BRT system.  This cost differential would continue over the 30-year period needed to repay the construction bonds.

It’s also likely that BRT could replace the 14-mile Initial Segment or the 21-mile Central Link system for less than half their costs. 

This information about a potential $900 million per year savings opportunity is new, and it needs to be published widely so taxpayers can decide whether it makes better sense to abandon Sound Transit’s light rail strategy and switch to an equally effective BRT alternative.

Itís unfortunate that knowledge of the BRT opportunity developed in 1993 has been suppressed.  The best explanation may be the major disconnect that exists between what most citizens of this region want (reduced traffic congestion at the lowest possible cost) versus what the members of the Sound Transit Board want -- light rail regardless the cost and despite the fact it won’t reduce congestion.

To paper over the gap, Sound Transit has systematically and continually resorted to disseminating biased, misleading, and even false information about the merits of Link light rail in order to bolster public support and justify Federal funding. One result is deterioration in the public’s trust in government to spend scarce tax dollars wisely. It’s also evidence that the current transportation planning process in Puget Sound is broken.  The process is not providing the through and objective information officials and voters need to make multi-billion dollar decisions.

This report finds that the very foundation of Sound Transit’s Draft Long-Range Plan of 2005 is invalid because it is based on one corrupted and obsolete study done in 1993. It recommends that Link be placed on hold until and unless a proper, honest alternatives analysis demonstrates that it is superior to BRT and other alternatives. This report further recommends that federal and local officials take steps to fix the process.

Click here for an extended summary with numerous illustrations.

Click here for the full report in pdf (1.3 megabytes).

Return to home page

Hit Counter