Often, after committing some bad things, the criminals try go away by car as fast as possible.
In the same way, some drug traffickers rush on the motorway at unauthorized rates. You need to chase them!
In chasing games, you have to accelerate and avoid obstacles such as traffic to pursue those who are trying to escape.
You sometimes have a limited time to catch the criminals then no loose time! Sometimes, you are the criminal, and you need to escape the police.