Southern section of St. Albans Bypass, now part of A414. It opened along with the M1 and M45 in December 1959, and was downgraded from motorway on 1st May, 2009.
Park Street Roundabout
Main Article: Park Street Roundabout
Park Street Roundabout is a major junction in Hertfordshire between the A405, A414 (the former M10) and the former A5 Watling Street, now numbered A5183. It is well known for being the example roundabout in the Highway Code, although the place names and road numbers are altered.