Complex sentence: Construction extending it to London began in 1972 and was completed in 1982, when the final link between Highway 81 and Highway 2 opened, and the entire route became a controlled-access highway with the removal of an intersection at Front Street in Sarnia.
Split into simpler sentences: Construction extending it to London began in 1972 and was completed in 1982, when the final link between Highway 81 and Highway 2 opened. The entire route became a controlled-access highway with the removal of an intersection at Front Street in Sarnia.