is regarded as the longest straight stretch of road in Australia and one of the longest in the world. The road stretches for without turning, and is signposted and commonly known as the "90 Mile Straight". Travelling east, the highway descends through the Madura Pass just before the Madura roadhouse from the Nullarbor Plain to the coastal Roe Plains. It skirts the bottom of the escarpment, climbing back through the Eucla Pass just before Eucla. Because of its remoteness, some widened sections of the highway serve as emergency airstrips for the Royal Flying Doctor Service. These airstrips are signposted, have runway pavement markings painted on the road, and turnaround bays for small aircraft. South Australia After crossing the border at the settlement of Border Village, the highway passes through the Nullarbor Wilderness Protection Area and then through the localities of Yalata, Penong and Ceduna. Before arriving at Ceduna, it enters the Eyre Peninsula. After Ceduna, the highway passes the intersection with Flinders Highway and heads south-east towards Kyancutta. After passing through Wirrulla, Poochera, Yanninee and Wudinna, the highway arrives at Kyancutta where it meets the north end of the Tod Highway. After Kyancutta, the highway turns to the east towards the town of Kimba. Before arriving at Kimba, it turns to the north-east. After Kimba, the highway passes through the southern end of the Lake Gilles Conservation Park and to the immediate north of both the town of Iron Knob and the Cultana Training Area before meeting the Lincoln Highway. It then continues north-east until it intersects with the Augusta Highway and Stuart Highway, north-west of the Joy Baluch AM Bridge which crosses Spencer Gulf at Port Augusta. An alternative route between Ceduna and Port Augusta, formerly signed Alternate National Route 1 and now signed B100, follows Flinders Highway and Lincoln Highway down the western and eastern sides of the peninsula respectively. History Background Edward John Eyre was the first European to traverse the coastline of the Great Australian Bight and the Nullarbor Plain by land, in 1840–1841, on an almost trip from Adelaide to Albany, Western Australia. Three decades later, the East–West Telegraph line was installed. Constructed between 1875 and 1877, it followed the same route across the Nullarbor and along the Great Australian Bight, after John Forrest retraced Eyre's route in 1870 and confirmed its suitability. Repeater stations were installed at Port Lincoln, Streaky Bay, Smoky Bay, Fowlers