'Agility' is not about doing the old thing faster. That may be only one dimension of it. It is not about pushing the pedal and acceleration. It is more about dynamics & dexterity. It is about ability to rapidly adjust your speed, accuracy and style swiftly to match the disrupted conditions on the new path.
The end purpose is to reach the destination fast and enjoy the journey. Unfortunately the old city is dead. You cannot use the old maps.