Missouri State Route 366 runs east-west in Eastern St. Louis County. This runs from the St. Louis/Shrewsbury City Limits to Interstate 44, at Sunset Hills. It is alos a old alignment of Historical U.S. Rt. 66. MO St Rt 366 passes through the following towns in St. Louis County. Shrewsbury
MO St Rt 366 is not multi-plexed in St. Louis County. MO St Rt 366 intersects the following highways in St. Louis County. Missouri Seocndary State Route P, at Shrewsbury.