A motorway linking a town and city in Hertfordshire is to be downgraded to accommodate a wider range of traffic.
The M10 between St Albans and Hemel Hempstead (M1 Junction 8) is to be reclassified as a new section of the A414 trunk road from 1 May.
There has been no direct road link for non-motorway traffic since the M10 was built, the Highways Agency said.
Traffic travelling between St Albans and Hemel Hempstead will no longer need to join a motorway.
John Dutson, Highways Agency project manager, said: "The reclassification of the M10, completed in 1959, so that it no longer has motorway status is good news for users of smaller motorcycles and learner drivers.
"Others who previously had to make a long detour to avoid the motorway will also benefit."