component projects are separately funded, with both the state and federal governments contributing to each project. Construction began in 2016, and was completed on 23 April 2020. Intersection Upgrades The federal government allocated $140.6 million to grade-separate Tonkin Highway's intersections south of Reid Highway, namely Benara Road, Morley Drive and Collier Road. The funding is part of the next five-year phase of the Nation Building Program, from 2014–15 to 2018–19. The upgrades are intended to improve freight transportation along the highway. The total cost is expected to be $281.2 million. In the lead up to the 2013 Australian federal election, which resulted in a change of government, Labor candidate for Perth, Alannah MacTiernan, accused the then-opposition's candidate of lying to the electorate over their commitment to the upgrade. The official policy costings did not contain specific funding for the project. However, an opposition spokesperson claimed it was "in the current forward estimates", and not in the costing, as the upgrade was neither a "new and accelerated" project, nor a project that would definitely not be funded. Northern extension Construction started in June 2017 to extend Tonkin Highway north, past Ellenbrook and through the Swan Valley to Brand Highway and Great Northern Highway in Muchea. Interchanges are planned at junctions with Reid Highway, Hepburn Avenue and Beechboro Road North, Gnangara Road, The Promenade, Stock Road, Neaves Road and Brand Highway and Great Northern Highway. The third stage was originally planned to be a two-lane single-carriageway road with at-grade intersections, with provision for upgrading in the future. However, during the tender process it was found that the ultimate plan with a four-lane highway and grade separation could be completed within the existing budget. The previously planned route of the PDNH, prior to 2012, followed Lord Street, east of Whiteman Park. The extension was opened in stages: the first section north of Reid Highway between Hepburn Avenue and Gnangara Road opened in January 2019 (which also saw Beechboro Road North between the two roads permanently closed at its northern end) with the section between Reid Highway and Hepburn Avenue making the highway continuous in March. Upon the opening of this section traffic was temporarily diverted onto what was the T-junction with Beechboro Road North and Gnangara Road, before eventually being transferred onto the new interchange. The highway was then extended to The Promenade in August 2019, completing the central section of the project.