No primary state highways directly serve Clifton. Access is provided solely by secondary routes, with SR 645 being the most prominent of them. Through Clifton, SR 645 enters from the northwest as Clifton Road, then turns right at Newman Road and follows Main Street to School Street. From there, it turns left onto School Street, then turns right and becomes Clifton Road again as it exits the town to the southeast. SR 645 provides connections to the nearest primary highways, U.S. Route 29 to the northwest and Virginia State Route 123 to the east.