M10 motorway (Great Britain)

The M10 was a motorway in Hertfordshire, England, running for approximately 3 miles (4.5 km) 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.HistoryThe M10 opened on 2 November 1959 along with the M1 and M45, and was designed and constructed by Tarmac Construction as part of the St Albans bypass (along with the M1 between junctions 5 and 10a).At the time, the M1's southern terminus was at junction 5 at Berrygrove, with the main route from there to the A1 in London being via the A41 Watford Bypass. Since the capacity of the A roads was much less than that of the motorway, a distributing spur was required to split up the traffic and reduce congestion at Berrygrove. The M10 was thus built to distribute southbound traffic on the M1 onto the A5 (now A5183) and, as an alternative, via the North Orbital Road and the A6 to the A1 Barnet Bypass.The M45 was the equivalent distributing spur at the northern end of the M1, and is thus regarded as a sister motorway to the M10.