The Raritan River Rail Road (reporting mark RR) was a 12-mile (19 km) shortline railroad in Middlesex County, New Jersey U.S., Founded in 1888, it was based in South Amboy, from which it ran west as far as New Brunswick. It served both passengers and freight in its heyday and operated profitably throughout much of its existence. The Raritan River was absorbed into Conrail in 1980, becoming a branch line of Conrail Shared Assets Operations. It terminates at U.S. Route 1 in North Brunswick.