to describe the main route from Midland to Geraldton, Western Australia. This was following the naming of the Great Eastern and Great Southern highways. The Midland Junction Municipal Council approved the name, with the last part officially opened on 16 December 1989 by Bob Brown and Bob Pearce, the federal and state transport ministers. This last section of the Great Northern Highway also completed the sealing of the National Highway,
Work on the Great Northern Highway has been continuous. From 2004 to 2010, the Muchea to Wubin section was upgraded, with parts reconstructed and realigned, and traffic lights installed at the intersection with Brand Highway. In the Kimberley, five sections between Halls Creek and Victoria Highway were improved between 2008 and 2009 with regards to pavement strength, alignment, safety, and flood resistance. From 2005 to 2010, the Perth section, through the Swan Valley, was upgraded, with the road widened, turning and overtaking lanes constructed, and street lighting improved. Construction of a realignment around Port Hedland's Wedgefield industrial area, including a new parclo interchange at Wilson Street, began towards the end of 2012. It was opened to traffic on 17 June 2014, and on 23 July 2014, Deputy Prime Minister Warren Truss, Federal Member for Durack Melissa Price, and Pilbara MLA Brendon Grylls officially opened the project. It was finalised in August. The project was completed and opened to traffic on 27 February 2015, and allowed the speed limit to be raised from .
A section between Batty Bog Road (north of New Norcia) and Walebing was reconstructed between September 2014 and 2015. Planning the alignment for the southernmost section, from Reid Highway in Perth to Bindoon, was undertaken from 2003 It resulted in the planned alignment commencing from Tonkin Highway, bypassing the Swan Valley and Bullsbrook before reconnecting with the Great Northern Highway near Brand Highway. The Great Northern Highway is then followed until the Brockman River, where the planned route deviates to the east to bypass Bindoon, reconnecting with the existing Highway near Bindoon–Moora Road.
The first stage of construction was undertaken as part of the NorthLink WA project. Tonkin Highway's original northern section was made grade separated, and a dual carriageway extended from the original northern end of Tonkin Highway (near Reid Highway) past Ellenbrook and through the Swan Valley to an interchange with the Great Northern Highway and a new part of Brand Highway, with the extension continuing on as the Great Northern Highway. The previously planned route of the bypass, prior to 2012, followed Lord Street, east of Whiteman Park. The project is funded by both the state and federal governments. Construction began in June 2017, and was completed on 23 April 2020.
Environmental hazards
As observed in the 2018 Broome flood, the highway, and its river crossings are always at risk in extreme weather situations.
In 2023, Rio Tinto lost a radioactive capsule somewhere along the Great Northern Highway between Perth and Newman. On 2 February 2023, the capsule was found by a search vehicle which detected its radiation south of Newman.
Future
Further upgrading is planned for the Great Northern Highway towards its southern end, as well as elsewhere along the highway. Planning has been completed for widening an section of Fitzroy Crossing, including replacing two single-lane bridges. , the project is awaiting federal approval, and construction is unfunded.
Muchea to Wubin Stage 2 Upgrade
In late 2015 Main Roads completed a planning review for an upgrade of the highway between Muchea and Wubin. Known as Muchea to Wubin Stage 2 Upgrade, the project continues work undertaken on this section from 2000 to improve the road to National Highway standards. Several bypasses, realignments, and other improvements have been planned at or near Muchea, Bindoon, New Norcia, Walebing, Miling, Pithara, Dalwallinu, Nugadong, and Wubin. Sections near Bindi Bindi and Batty Bog, completed in 2015, were included in the review.
Bow River bridge
The project for replacement of the existing low-level single lane bridge with a new two-lane high-level bridge was completed in late 2018 at a total cost of $23.2 million.
Ord River north section (stage 2)
The project for widening and reconstruction works, including building a new bridge over Tickalara Creek
Beef road upgrade
The Northern Australia Beef Roads Program announced in 2016 included the following project for the Great Northern Highway.
Ord River north section (stage 1)
The project for widening, overlay and reconstruction works, including realigning of road was completed in late 2019 at a total cost of $15.6 million.