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)

By the 1960s and 1970s, Portland was violating federal clean-air standards on a consistent basis. Concurrently, a controversial new freeway, the Mt. Hood Freeway, was in the planning stages. This freeway would have sliced through Southeast Portland, forcing thousands to relocate. Grass-roots efforts around the city called attention to the general distaste for new freeways and affected local elections. These efforts resulted in the election of anti-freeway politicians to city and county offices, and these new administrations successfully lobbied and abandoned the Mt. Hood Freeway plan.

TriMet was established in 1969 after the previous transit provider, Rose City Transit, was not doing enough to generate ridership while meeting federal air quality standards and went bankrupt. TriMet quickly absorbed many of the outlaying suburban bus services over the next few years. TriMet also began preparing for rapid transit solutions, opening the Portland Transit Mall to buses in 1975 and studying light rail. After the decision was made to kill the Mt. Hood Freeway in the 1970's, light rail in Portland went to the forefront of plans to improve the traffic problems in the Portland Metro Area. Momentum increased when legislation was passed in the U.S. Congress to allow funds from abandoned freeway projects to be used for urban transit projects. Residents voted in favor of constructing what was then called the Banfield Light Rail Project, named for the freeway (I-84) which the majority of the alignment followed.

In September 1986, the Eastside MAX line opened for revenue service, spanning 15 miles from Gresham to downtown Portland. One of the first light rail systems in America, Eastside MAX helped set the standard for the future of American light rail design. It also marked a critical point in Portland’s history, as the region went away from automobile-focused urban design to become a civic leader in land use and transportation.

In 1998, the Westside MAX line, TriMet’s first extension of its light rail network, opened for revenue service, spanning 18 miles from the fast-growing high-tech corridor in Hillsboro to downtown Portland. One of the largest public works projects in Oregon’s history, it included twin tunnels, each tunnel being 21 feet in diameter and spanning three miles through Portland’s West Hills area.