"Street Running" refers to a train traveling the middle of a street where cars normally travel. Sometimes its just not possible to have the tracks run along side a street, or vise versa. Here in the Pacific Northwest there’s a small handful of places to see street running. The old Oregon Electric line probably has (or had) the most.
There is some in Hillsboro, Salem, and down in Harrisburg and Junction City, OR near the southern end of the OE. Hillsboro is west of Portland. When BN removed the branch line from Forest Grove Jct. to Hillsboro, this part of the BN became a small island separated from the rest of the BN. The track down the middle of Washington Street is the former SP&S, former BN tracks, while the track running down the middle of SW Adams is former Southern Pacific.
The most famous, and probably the most photographed, location for street running in the Northwest has to be in downtown Renton, WA where the old Pacific Coast Railroad mainline runs right down the middle of Houser Way South. The tracks enter the street at the intersection of South 4th Street and Burnett Ave S at the west end, and exit on the east side of Houser Way at Mill Avenue South. Up until the mid-1970s Milwaukee Road Little Joes could be seen running down the middle of the street. The Milwaukee Road disappeared in 1980. Then in the late 1980s came the Spirit of Washington Dinner Train for a period of time, now just Boeing 737 fuselages travel down Houser Way.