|The highway viewed near the eastern portal of the Heysen Tunnels|
|Length||10 km (6 mi)|
|Route number(s)||National Highway M1|
|West end||Glen Osmond Road, Glen Osmond, Adelaide|
|East end||South Eastern Freeway, Crafers, Adelaide|
|Major suburbs / towns||Mount Osmond|
|Highways in Australia
National Highway • Freeways in Australia
Highways in South Australia
The Adelaide–Crafers Highway is a 10 kilometre controlled-access highway linking Adelaide city centre to Crafers in the Adelaide hills, and continuing from Crafers as the South Eastern Freeway. The highway is ten kilometres long, including 500 metre long twin-tube tunnels (the Heysen Tunnels), the first of their kind on the National Highway. The road is signed as the Princes Highway for its entire route from Glen Osmond Road to the South Eastern Freeway. It is designated as the M1.
The Adelaide–Crafers Highway came as a much-needed upgrade and replacement to the previous link road, the Mount Barker Road, which had been contoured to the Adelaide Hills, giving rise to many steep turns, ascending a tortuous route. The tightest hairpin turn on the Mount Barker Road became infamous as 'the Devils Elbow', often the site of car and semi-trailer accidents.
On 16 May 1995, Prime Minister Paul Keating announced the construction of the new freeway. The Heysen Tunnels, named after well-known South Australian artist and benefactor Hans Heysen, were completed in 1998. Construction was completed early 2000 and on 5 May 2000 Prime Minister John Howard opened the new road. It was the largest South Australian road project, costing a total of A$151 million, wholly funded by the Australian Federal Government.
The Adelaide–Crafers Highway features 6 lanes of traffic, arrester beds and concrete median barriers, with street lighting through all 10 km.
Shortly after the Adelaide-Crafers Freeway opened, several incidents involving semi-trailers drew media attention to the road: particularly after a high-profile media identity was involved in a near-fatal accident with a semi-trailer. While the previous Mount Barker Road was a notorious stretch, its dangers were well known - the new freeway presented the new challenge of a sustained continuous gradient. Heavy vehicles with inadequate braking found it hard to slow down once they had exceeded a certain speed; this was made worse with brake failures. It took some time, and the addition of several warning signs prior to the descent, for heavy vehicles to become familiar with the freeway's characteristics. Semi-trailers can been seen travelling as slow as 20–30 km/h downhill. In 2005 changeable electronic road signs were installed every 200 metres, so that the speed limit of the road can be adjusted from Transport SA headquarters in Adelaide. This has both improved safety for commuters, and emergency service workers like the Country Fire Service.
In 2010 and 2011, after several incidents involving trucks having problems successfully braking down the hill, one of which going into a bus stop, and another going straight through the intersection at the bottom, the government added new laws that any vehicle with 5 axles or more must stay in the left lane and must not exceed a 60 km/h limit from the interchange at Crafers to the old tollhouse. More Safety cameras are installed in an attempt to ensure trucks abide by this new limit.
Additional signs for the two arrester beds on the descent have also been added, to encourage out of control drivers to use them as a safer alternative.
In August 2014, another truck collided with many cars at the lower part of the highway, killing two people. Brake failure was suspected to be the cause of the accident.
Exits and intersections
|Burnside–Unley–Adelaide tripoint||Glen Osmond–Urrbrae–Myrtle Bank tripoint||0||0||Glen Osmond Road (A1) north-west / Cross Road (A3) west / Portrush Road (National Highway A17) north||North-western highway terminus at traffic lights|
|Burnside||Mount Osmond||2.2||1.4||Mount Osmond Road||Four ramp parclo interchange|
|Mount Barker Road||South-eastbound exit and north-westbound entry only; location of the Devils Elbow on Mount Barker Road|
|Adelaide Hills||Crafers West||6.7||4.2||Mount Barker Road – Eagle On The Hill||North-westbound exit and south-eastbound entry only|
|Crafers||8.0||5.0||South Eastern Freeway (National Highway M1) south-east / Mount Lofty Scenic Drive , Melbourne, , Mount Lofty||South-eastern highway terminus|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- Highway 1 (Australia)
- Highway 1 (South Australia)
- South Eastern Freeway
- Highways in Australia
- List of highways in South Australia
- Freeways in Australia
- Freeways in South Australia
- Metropolitan Adelaide Transport Study
- "Old and New Road Names". City of Burnside. 8 March 2006. Retrieved 2007-07-14.
- "The Adelaide Crafers Highway Project". Government of South Australia, Department for Transport, Energy and Infrastructure. 13 August 2004. Archived from the original on 2007-08-29. Retrieved 2007-07-14.
- Google Inc. "Adelaide–Crafers Highway". Google Maps (Map). Cartography by Google, Inc. https://maps.google.com.au/maps?saddr=National+Highway+M1&daddr=National+Highway+M1+to:National+Highway+M1+to:National+Highway+M1+to:National+Highway+M1+to:National+Highway+M1+to:National+Highway+M1+to:National+Highway+M1&hl=en&ll=-34.978111,138.683338&spn=0.071523,0.104628&sll=-34.969764,138.660529&sspn=0.004471,0.006539&geocode=FUKA6v0do4pDCA%3BFbVn6v0diclDCA%3BFRtx6v0d-OBDCA%3BFcdw6v0dj-9DCA%3BFaJa6v0dnglECA%3BFZ5M6v0dWBZECA%3BFUge6v0daFBECA%3BFXT56f0dfW5ECA&mra=dme&mrsp=1&sz=18&t=m&z=14. Retrieved 15 January 2014.