Solving Stray Current Mitigation In Portland’s Rail System

By Aaron Eder, P.E. | August 2014, Vol. 69, No. 8
Rendering of the Portland-Milwaukie light rail system. (photo courtesy of TriMet)

From the modest beginnings of horse-drawn rail cars on First Avenue in the early 1870s, light rail in Portland, OR, has flourished, declined and gone through a resurgence.

By 2030, planners forecast a million new residents in the Portland metropolitan area. The Portland-Milwaukie Light Rail project is a key component in the planning effort connecting Clackamas County, one of the region's fastest-growing areas, with Portland State University (PSU), the number one destination in its transit system. Light rail systems such as this impose unique impacts to utilities within the light rail corridor. This fast-tracked project mitigates those impacts while reducing construction duration and cost and minimizing the impacts to businesses along the alignment.

The South Corridor Project –led by Metro in partnership with Tri-County Metropolitan Transportation District of Oregon (TriMet), the city of Portland, the city of Milwaukie and Clackamas County – has worked to identify transportation options for the fast-growing Interstate 205 (I-205) and Milwaukie/Oregon city corridors. When the study began in 1999, light rail was not an option under consideration. But neighborhoods along the alignment – from Southeast Portland to Milwaukie – requested that light rail be part of the study and it was ultimately adopted as the preferred option.

Subsequently, the South Corridor Project has followed a two-phased approach. In September 2009, Phase 1 brought Metropolitan Area Express (MAX) Green Line service to the I-205 corridor between Clackamas Town Center and Gateway, where it then uses the existing MAX Blue and Red line tracks to travel to downtown Portland. Once the Green Line crosses the Steel Bridge, it follows new tracks along the Portland Mall to Portland State University. Portland-Milwaukie light rail constitutes Phase 2 of the South Corridor Project, with Phase 1 being Portland Mall light rail.

History

In the 1870’s, Portland’s first trolleys were horse- and mule-drawn, operating on First Avenue from NW Glisan Street to SW Caruthers Street. As the 1900s came, the Portland metropolitan area had the first interurban electric rail service in the nation. By 1912, Portland saw its high point of 28 electric rail lines, when the population of the city was 250,000. However, after World War I, electric rail lines began to feel the pinch from the emergence of the automobile. During the Depression in the 1930s, streetcars began being replaced with buses and in 1950, the last street car was retired.