still known today as Greensborough Road. Construction on the northern half, the 3 km section between Grimshaw Street and Diamond Creek Road, started in 1985 and opened in March 1988 (this section was later declared a State Highway in 1989); construction on the southern half, the 2 km section between Grimshaw and Lenola Streets, started in late 1985, and opened in September 1989. The passing of the Transport Act of 1983 (itself an evolution from the original Highways and Vehicles Act of 1924) provided for the declaration of State Highways, roads two-thirds financed by the State government through the Road Construction Authority (later VicRoads). The Greensborough Highway was declared a State Highway in December 1990, from Banksia Street in Heidelberg to Diamond Creek Road in Greensborough (incorporating the newly constructed road previously declared as a State Highway the year before); however the road was still presently known (and signposted) as its constituent parts. Throughout the 1990s the Metropolitan Ring Road was constructed, terminating at the Greensborough Bypass section of the highway. Around this time, the road north of Grimshaw Street was progressively widened and duplicated, with the final section being a new bridge over the Plenty River, completed in 2005. The passing of the Road Management Act 2004 granted the responsibility of overall management and development of Victoria's major arterial roads to VicRoads: in 2004, VicRoads re-declared the road as Greensborough Highway (Arterial #6850), from Banksia Street in Heidelberg to Heidelberg-Kinglake Road (known as Diamond Creek Road) in Greensborough; as before, the road is still presently known (and signposted) as its constituent parts. Timeline of construction 1988: Northern section of Greensborough Bypass, initial 3.5 km of dual-lane, single-carriageway road from Grimshaw Street to Diamond Creek Road, opened 1 March 1988. 1989: Southern section of Greensborough Bypass, 2 km of dual-carriageway road from Grimshaw Street to Yallambie Road, opened September 1989. 1998: Greensborough Bypass duplication, 1.3 km north of Grimshaw Street to Metropolitan Ring Road (including bridge over Kempston Street and provision of additional lane east of Plenty River). 2005: Greensborough Bypass duplication, 1.8 km Metropolitan Ring Road to Diamond Creek Road, including duplication of Plenty River bridge. 1969 Melbourne Transportation Plan The route was originally designated in the 1969 Melbourne Transportation Plan as the F18 Freeway, extending further than Diamond Creek Road to finish at Ryans Road, Diamond Creek, and at the southern end extending past Lower Plenty Rd to