the new Swanport Bridge over the River Murray opened in 1979. This provided an alternative to the historic bridge in Murray Bridge. The Adelaide–Crafers Highway extension 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 was infamous as the Devil's Elbow, often the site of car and semi-trailer accidents. In May 1995, Prime Minister Paul Keating announced the construction of the new Adelaide-Crafers section. The Heysen Tunnels, named after well-known South Australian artist and benefactor Hans Heysen, were completed in 1998. Construction was completed in early 2000. In March 2000, Prime Minister John Howard opened the new road. It was the largest South Australian road project at that time, costing A$151 million, wholly funded by the Australian Federal Government. An additional exit was built at Monarto around 1999 to service an expanding commercial zone and the Monarto Zoo in the area. Another exit was announced in 2014 at Bald Hills Road, 4 km southeast of the Mount Barker interchange to service growing housing estates in southern Mount Barker and Nairne. Bardavcol started construction in May 2015, with the interchange including entry and exit ramps in both directions. The $27M project was funded $16M by the Australian government, $8M from South Australia and $3M from Mount Barker district council. The new interchange opened in August 2016. The Freeway bypasses many towns previously along the Princes Highway, including: Eagle On The Hill Crafers Stirling Aldgate Bridgewater Verdun Hahndorf Mount Barker Littlehampton Nairne Kanmantoo Callington Monarto Murray Bridge Road safety Shortly after the Adelaide-Crafers section opened, several incidents involving semi-trailers drew media attention to the road. The new freeway has a sustained continuous gradient with traffic lights at the bottom. Heavy vehicles with inadequate braking find it hard to slow down once they exceed a certain speed. This is 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 be 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