When a light-rail line was constructed parallel to an existing interstate highway near Portland Oregon, it crossed five pressurized, large-diameter (60-in [1,524-mm]) steel water transmission pipelines that carry drinking water into the city from nearby reservoirs. The transit corridor was considered a high-consequence area because a pipe failure could disrupt both light-rail and highway traffic. To protect the pipes in the transit corridor where they crossed underneath the light-rail tracks, construction of the line included retrofitting the pipelines with a precast concrete box culvert casing and installing an impressed current cathodic protection (ICCP) system.
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