Following delays, the project as a whole was eventually completed when the northern section officially opened on 23 April 2020. Dunreath Drive Dunreath Drive, a local road that originally ran parallel with Tonkin Highway to the east, provided an alternative route between the Perth Airport terminal buildings. Significant changes were made to the road during the evolution of Tonkin Highway during the 2010s and into 2020. On 16 April 2012, an intersection linking Dunreath Drive with Tonkin Highway was opened. This traffic light controlled at-grade intersection allowed a more direct access to and from the international terminal of Perth Airport, bypassing Tonkin Highway's intersections with Leach Highway and Kewdale Road/Horrie Miller Drive. However, the intersection did not allow northbound travellers to bypass the Great Eastern Highway interchange in order to access the domestic terminal. The intersection was later removed on 16 July 2015 as part of the work with Gateway WA. In its place was a dogbone interchange linking Tonkin Highway to Dunreath Drive, allowing full movements to and from the T3/T4 precinct. Since commissioning, the area between the two roads was significantly developed, with a Direct Factory Outlet centre opening in 2018, followed by a Costco in 2020. Due to the increase of traffic the eastern roundabout was removed during the first half of 2020, with the western roundabout seeing peak traffic signals installed. Future works A number of improvement works are planned for Tonkin Highway, which will see most of the central and northern sections upgraded to a freeway-standard road with grade separated interchanges. The southern end is also planned to be extended to South Western Highway south of Byford. Tonkin Highway "Gap" As a result of the upgrades north and south of the Swan River, the section between the Collier Road and Dunreath Drive interchanges has become known as the Tonkin Gap, where the road reduces from six to four lanes crossing the Swan River, Guildford Road, Railway Parade and the Midland line. There are plans to widen this section of highway to six lanes, including duplication of the Redcliffe Bridge. It is also planned to build north and southbound collector-distributor roads between Guildford Road interchange and Great Eastern Highway interchange (which will also receive an additional westbound to northbound loop ramp) and a fully grade separated principle shared path (PSP) on the western side of Tonkin Highway from north of Guildford Road interchange to Stanton Road.