Abigroup Leightons Joint Venture Supply of 40km Flexfence Wire Rope Barrier Supply of 2km Guardrail Supply of 10 TRACC Crash Cushions Westlink M7 is a 40km motorway linking the M2, M5 and M4 motorways. Costing $1.5 billion to construct, the motorway contains two traffic lanes in each direction, separated by a central median. The motorway facilitates faster travel in western Sydney, containing 17 interchanges and bypassing 48 sets of traffic lights.