Complex sentence: Legislative restrictions were implemented at some stages to limit competition from road transport, most notably from the 1930s through to the 1950s, when the Transport Co-ordination Board kept strict control over trucking, buses and commercial road traffic.
Split into simpler sentences: Legislative restrictions were implemented at some stages to limit competition from road transport. Notably in the 1930s through to the 1950s the Transport Co-ordination Board kept strict control over trucking, buses and commercial road traffic.