Original sentence: The completed M4 followed its original route for only three years: until the diversion via the Second Severn Crossing opened in 1996.The development will not only build two extra bridges and re-route many roads by the junction but will also involve the movement of the local Highways Agency and Fire Service offices and build a long footbridge network, a special bus-lane, and a new gyratory.Unusually for a toll road, tolls are charged in one direction only: westbound
Edited sentence: The completed M4 only followed its original route for three years, until the diversion via the Second Severn Crossing opened in 1996.The development will not only build two extra bridges, and re-route many roads by the junction, but will also involve the movement of the local Highways Agency and Fire Service offices, build a long footbridge network, a special bus-lane and a new gyratory.Unusually for a toll road, tolls are charged in one direction only - westbound