Greensborough Highway is a highway in the north-eastern suburbs of Melbourne, Australia, and is an important route for north-east Melbourne. This name is not widely known to most drivers, as the entire allocation is still best known as by the names of its constituent parts: Lower Heidelberg Road, Rosanna Road, Lower Plenty Road, Greensborough Road and Greensborough Bypass. This article will deal with the entire length of the corridor for sake of completion, as well to avoid confusion between declarations. Route Lower Heidelberg Road starts at the intersection of Heidelberg Road and Upper Heidelberg Road in Ivanhoe and heads east as a four-lane, single-carriageway road through Eaglemont, crossing Banksia Street at Heidelberg (and the beginning of Greenborough Highway), nearly immediately crossing Burgundry Street and changing name to Rosanna Road to Rosanna, where it intersects with and changes name to Lower Plenty Road and widens to a six-lane, dual-carriageway road. It continues north-east, where after a short distance it intersects with and changes name to Greensborough Road, heading north as a four-lane, single-carriageway road until it meets Watsonia Road in Watsonia, changing names to Greensborough Bypass and continues north-east as a six-lane, dual-carriageway road, crossing Grimshaw Street and turning east at the intersection with Metropolitan Ring Road in Greensborough before eventually ending at the roundabout with Diamond Creek Road and Civic Drive. History Lower Heidelberg Road and Rosanna Road were signed as Metropolitan Route 44 between Ivanhoe and Yallambie in 1965; Greensborough Road was also signed as Metropolitan Route 46 in 1965, originally turning east along Grimshaw Street to run through Greensborough and along Diamond Creek Road east beyond it. When the Greensborough Bypass was opened in the late 1980s, Metropolitan Route 46 was re-aligned along it to bypass Greensborough and re-join Diamond Creek Road beyond. In the late 1980s, the northern section of Greensborough Road south of Grimshaw Street was extended and significantly altered, with the original road north of Lenola Street in Macleod re-aligned to the west as a service road, the new road being a divided highway up to a new intersection at Grimshaw Street. North of here the road was extended as a single carriageway bypass road, sweeping north-west around central Greensborough and terminating at a large roundabout interchange with Diamond Creek Road and Civic Drive, known locally (and sign-posted) as the Greensborough Bypass. The original alignment north of Nepean Street was repurposed for local traffic only,