Built as a spur to the A45 towards Coventry and Birmingham when the original M1 was built in 1959. It is D2M and is extremely quiet. It is currently almost original, with the exception of the junction in the middle which acts as a bypass of the village of Dunchurch.
Main Article: Kilsby Interchange
The Kilsby Interchange is the junction linking the M45 to the M1. It is a south-facing fork, and the oldest motorway-motorway interchange in the United Kingdom.