returned to its usual operations, repairing and maintaining the road network. The rural road network expanded in the 1950s, with Main Roads both repairing the worst segments of its roads, through numerous small jobs, and assisting local governments to seal their roads. Such activity was spurred on by the closure of railway lines in addition to the establishment of new land settlements. In Perth, a roundabout was constructed at the north-western end of Albany Highway, to improve the flow of traffic onto and off The Causeway. It opened in 1952, with guides on the usage of the roundabout published in newspapers. In 1973 construction began to upgrade the intersection to a partial cloverleaf interchange at the eastern end of The Causeway. The $1.3 million interchange opened on 8 March 1974. By the late 1970s, the road sections sealed in the 1950s and 1960s were in need of repair or maintenance to prolong the pavement life. Old bitumen surfaces would deteriorate and crack. Resealing such cracks was a high priority, as expensive reconstruction would be required if water was allowed to enter the road base. Over a ten-year period, $49 million was spent on repairing Albany Highway. The techniques used in this process were then formalised into the 4R Program, which aimed to alleviate a growing maintenance problem – based on a thirty-five-year pavement lifespan, the amount of reconstruction required would be more than double the actual rate of reconstruction. "4R" abbreviated the options that could be used keep roads serviceable: Restoration – maintaining the condition of a road Resurfacing – resealing a bitumen surface which was no longer waterproof, to prevent pavement failure Rehabilitation – improving a deteriorated road to its original condition Reconstruction – done when deterioration was beyond the point of repairs Interventions to prevent a road requiring reconstruction, the most costly option, would save money. From the 1980s Main Roads began planning for the future needs of Albany Highway within the City of Canning in Perth, in conjunction with the City and the Metropolitan Region Planning Authority. A section between Leach Highway and Nicholson Road was subsequently upgraded between November 1992 and June 1994. The four-lane undivided road had been one of the most congested in Perth but was improved by adding a third lane in each direction as well as a median strip. The project was recognised with an Excellence Award from the Institution of Engineers