The Ayer Rajah Expressway (AYE) spans 26.5 km and runs from the western end of the East Coast Parkway (ECP) to Tuas in the west. It also connects to Malaysia via Tuas Second Link.
Construction for the AYE began in 1983 and was completed in 1988. The work included widening of some of the existing roads like the Ayer Rajah Road and Upper Ayer Rajah Road.
The Keppel Viaduct is also part of AYE and spans 2.2 km.
The AYE passes through the industrial estate Ayer Rajah, thus deriving its name.
The AYE covers Tuas, Clementi, West Coast, Bukit Merah and Keppel areas.
Together with the East Coast Parkway, the AYE forms a second east-west link.