This Paper deals with the design and construction of the Sighthill section of the Edinburgh City bypass, and pays particular attention to the more unusual aspects of the project. These aspects include the geology and ground conditions encountered, the construction of an aqueduct to carry the Union Canal over the bypass, general environmental considerations, including the rehabilitation of a small village, the diversion of the main Edinburgh/Carstairs railway for a temporary period, and a general description of the construction logic and associated problems. The pressing need for a dual-carriageway bypass around Edinburgh has been such that Lothian Regional Council (LRC) has maintained a continuing construction programme aimed at completion by 1990. With a length of some 5 km the Sighthill section of the Edinburgh City bypass was the second of five major roadworks contracts forming a route which will eventually be some 23 km long. Beginning at Glasgow Road (A8), immediately west of the bridge over the Edinburgh/Aberdeen railway, the line of the new bypass follows a generally south-easterly alignment, terminating at its junction with the Musselburgh bypass close to Old Craighall village. The entire project, together with the Musselburgh and Portobello bypasses, has an estimated overall cost of 126 million. A proportion of the City bypass costs have been met by both Central Government and the European Regional Development Fund, and additional funding has been made available by the European Investment Bank. The Sighthill project was designed principally by the Department of Highways staff of LRC, and the 12.6 million contract for the construction was awarded to Balfour Beatty Construction (Scotland) Limited. Site work began in September 1984 and completion was achieved in December 1986, some nine months ahead of programme. Included in the project were the construction of 5 km of main carriageway, 3 km of associated roads, of which 1 km was dual carriageway, and the erection of 18 structures ranging from a simple retaining wall to the 90 m long aqueduct carrying the Union Canal in a navigable channel over the new road. The construction of this aqueduct, together with measures to counteract settlement of embankments, the temporary diversion of the Edinburgh/Carstairs main railway line, the unusual amount of tunnelling required for the re-routeing of sewers, and the uncommonly high profile given to landscape planting are all aspects of the contract which are dealt with in this Paper. (Author/TRRL)