Complex sentence: The M45 motorway was constructed in 1959 parallel to part of the old A45 route in the Midlands and opened on the same day as the M1 motorway and was soon one of the busiest sections of motorway.
Split into simpler sentences: The M45 motorway was constructed in 1959 parallel to part of the old A45 in the Midlands. It opened on the same day as the M1 motorway and was soon one of the busiest sections of motorway.