OREGON
TRANSPORTATION
INSTITUTE
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Analysis of the Westside Corridor Travel Study
Did Westside Light Rail Really Reduce Traffic Volumes?
Auto volumes were not reduced in the westside corridor (also called the Sunset Corridor because the freeway abutting the westside light rail line, Highway 26, is called the Sunset Highway) despite the presentation of largely irrelevant data and tortured conclusions provided in the Westside Corridor Travel Study (WCTR).
The following traffic volumes were measured by ODOT’s permanent counters at the Vista Ridge tunnel (the only permanent counter on the Sunset Hwy). All week day counts were averaged for the months of May for the years 1996 to 1999 except for holidays. If a counter was not functioning in one direction, both directions were omitted. The month of May was used because that is the last month used in the WCTR. But unlike the WCTR, we did not use October data in one year and May data in another because each month of the year has different usage characteristics. For example, September traffic volumes are more than 5% lower than August and October volumes are lower than September.
YEAR EASTBOUND WESTBOUND COMBINED % INCREASE
1996 71,951 70,998 142,950
1997 72,586 71,029 143,615 0.46%
1998 72,978 70,919 143,897 0.20%
1999 73,494 71,805 145,299 0.96%
This data shows that Sunset Highway traffic volumes increased subsequent to the opening of MAX in September 1998 and that the rate of increase more than doubled.
The parallel routes, Barnes and Cornell Roads, also registered a net increase compared
to May 1997 and 1995, the only May data previously measured by the Westside Corridor
Project. Another measurement used in the report was Beaverton-
A conclusion reached by the WCTR was that “Daily traffic in and out of downtown increased just 6 % while employment in Multnomah county grew 11 %.” But Willamette Week’s Bob Young (using Metro data) reported on June 17, 1998 that employment ”downtown” declined between 1990 and 1996 and is not growing. The growth in employment in Multnomah County is occurring elsewhere. The increase in traffic downtown must be compared to zero growth, another confirmation of increased auto use.
The WCTR stated that “Traffic volumes on major roads in Washington County have increased 17 % while employment grew 26 % .” This 1993 to 1999 data could be interpreted to be positive only if one were to assume that all of the employment increase resided elsewhere and had to commute to Washington jobs on the western edge of the urban growth boundary. This is highly unlikely since Washington County population increased more than the number of jobs. A more likely assumption is that a large percentage of the jobs, particularly those filled by individuals from other areas, were filled by people locating close to the jobs making less use of the “major roads.”
The WCTR does many other things which distort both traffic volumes and transit usage and the comparison of one to another. The selection of a screenline (measurement location) for transit usage on 18th Street which includes trips from Goose Hollow and Northwest District, irrelevant to the Sunset Corridor, inflates Sunset Corridor transit usage, particularly when Eastbound counts are of riders leaving the MAX station or bus stop and westbound counts are of riders arriving at the MAX station or bus stop.
Basing conclusions on peak hour usage distorts accuracy because transit’s peak hour usage is much greater than the hours immediately preceding and following hours while road traffic volumes are relatively level over many hours.
WCTR trumpets that “Transit’s share of reverse commute trips in the morning has more than doubled (+114 %) since 1997.” While the WCTR percentage is correct, it misleads the reader. The increase in all reverse trips was only 776 users, accepting what we believe to be inflated counts because of the screenline placement. That is at a time when only the major parallel roads are carrying 17,000 in the same direction and after a huge (46%) increase in corridor transit capacity.
The fact that west side light rail has not had any beneficial effect on west side congestion comes as no surprise to the folks who commute there each day and to east side commuters who have been waiting for congestion relief on the Banfield since east side light rail opened in September 1986.