Illinois State Route 164 is a east-west surface highway in Northern Warren County. It provides a alternative highway to the U.S. Rt. 34 expressway, between Monmouth and Galesburg. IL St Rt 164 passes through the following towns in Warren County. Monmouth
Coldbrook IL St Rt 164 is multi-plexed in Warren County. U.S. Rt. 34, near Monmouth.