Wisconsin State Route 318 is a north-south highway in Central Waukesha County. It runs along the eastside of the City of Waukesha. WI St Rt 318 passes through the following town in Waukesha County. Waukesha WI St Rt 318 is not multi-plexed in Waukesha County. WI St Rt 318 intersects the following highways in Waukesha County. Interstate 94, at Pewaukee. TEMP U.S. Rt. 18, at Pewaukee. U.S. Rt. 18, at Waukesha.