The M10 was a motorway in Hertfordshire, England, running for approximately 3 miles (4.5 km) southeast from the M1 motorway at junction 7 near Hemel Hempstead to the A414 North Orbital Road at Park Street Roundabout, just south of St Albans. Opened in 1959, it was reclassified as part of the A414 in 2009 having only been a spur motorway for about 50 years.