RSB meaning in Regional ?

The Rochester Industrial and Rapid Transit Railway (reporting mark RSB), more commonly known as the Rochester subway was a light rail rapid transit line in the city of Rochester, New York, from 1927 to 1956. The subway was constructed in the bed of the old Erie Canal, which allowed the route to be grade-separated for its entire length. Two miles (3.2 km) of the route through downtown were constructed in a cut-and-cover tunnel that became Broad Street, and the only underground portion of the subway. The Rochester Subway was designed to reduce interurban traffic on city streets, and to facilitate freight interchange between the railroads. The line was operated on a contract basis by New York State Railways until Rochester Transit Corporation (RTC) took over in 1938. The last day of passenger service was June 30, 1956. Portions of the right-of-way were used for expressway construction, while the rest was abandoned and filled in over the years. The largest remaining section is a stretch of tunnel under Broad Street from Exchange Street to the intersection of Court Street and South Avenue.