Complex sentence: The road has been re-routed several times in the last 100 years.Part of the route of the London section of the A40 was laid out in the 1920s and 1930s when Western Avenue was built, although most of it is now grade-separated dual carriageway.
Split into simpler sentences: The road has been re-routed several times in the last 100 years. Much of the route of the London section of the A40 was laid out in the 1920s and 1930s when Western Avenue was built, although most of it is now grade-separated dual carriageway.