EXPANDING AN EXISTING LIGHT RAIL SYSTEM. TECHNICAL DEVELOPMENTS IN PORTLAND

In the late 1970s, when LRT was first contemplated in Portland, the mode was largely unknown in the Northwest. Only in san Francisco was there a remnant streetcar operation, little of its relevant to a new LRT system. Much of Portland's new LRT was based on European concepts, still unproven at that time in the U.S. In 1986 the 15-mile long first line was opened, and, surprise, it worked just like it was suppose to! Popular support soared, and a second line was approved by the voters. This line adds 18 miles to the system, and is now well into construction for a 1998 opening. In 1993 planning started for the third and fourth lines, known as the South/North Project, running from south to north across the city. Almost 20 years after the first line was planned, this project is being developed in partnership with a community and public officials far more familiar with LRT. Some issues that raised concerns 20 years ago are now accepted practice. Design practices that were one state of the art for rail transit are now found to have shortcomings, and new concepts have been developed. Some parts of the community compete for stations, while others want the line to go elsewhere. LRT is often seen as a means to upgrade streets and urban quality conflicting with mounting pressure to hold down project costs. This paper outlines Portland's next light rail extension, and describes a number of ways in which the design concepts have evolved in the light of 10 years of operating experience.