from the east. Upon reaching the commercial downtown of Hightstown, northbound CR 539/CR 571 join Route 33 as it merges from Mercer Street onto Main Street. (Traveling southbound, CR 539/571 follow Route 33 onto Mercer Street for one block before turning east onto Ward Street and then south onto South Main Street.) CR 571 then leaves the concurrency by turning to the west on Stockton Street. After crossing the Rocky Brook, Route 33 splits from CR 539 by turning to the east on Franklin Street while CR 539 continues on North Main Street past more homes, intersecting CR 633. The road heads back into East Windsor Township and runs through farmland, passing under Route 133. The road passes near housing developments, becoming South Main Street as it crosses the Millstone River into Cranbury Township, Middlesex County, in wooded areas. CR 539 reaches an intersection with US 130 a short distance later at a modified traffic circle. Continuing north along South Main Street, CR 539 ends at a signalized intersection with CR 535 and CR 685 (Old Trenton Road). History When the 500-series county routes were first designated in the 1950s, CR 539 traveled west from Hightstown to Princeton on Stockton Street, Princeton–Hightstown Road, and Washington Road, the route of present-day CR 571. It became CR 571 by 1976. More recently, the state had previously designated CR 539's northern terminus to be at the US 130 traffic circle though signage at and around the intersection showed CR 539 continuing north of the circle. CR 685 was the official designation for this portion of South Main Street. By 2019, the current terminus had been established by the state. Two special routes of CR 539 existed at the creation of the 500-series county routes. County Route 539 Spur ran from Warren Grove to Waretown. The road today is now Ocean County Route 610 from CR 539 to Route 72, and CR 532 from Route 72 to its current end at US 9 (CR 532 at the time ran on what is now CR 554). This designation was removed by 1961. County Route 539 Alternate followed what is now CR 526 from Allentown to Princeton Junction. It was renumbered as a western extension of CR 526 by 1956. A Monmouth County-takeover of Sharon Station Road in Upper Freehold known as County Route 539 Alternate occurred in 2009. Parts of CR 539 in Ocean and