Sprawl works well to reduce traffic only if the sprawl develops well enough so there's no real reason for people to travel between regions regularly. Otherwise

Sprawl works well to reduce traffic only if the sprawl develops well enough so there's no real reason for people to travel between regions regularly. Otherwise, it'll most definitely increase traffic. Why wouldn't it? Increasingly large population spread over an increasingly large area, with all the traffic only going in a few specific directions.