As discovered by Drinky, and probably known by Travis. Lets take the bus driver job as an example, If you are in the middle of your route, you can cancel your route by going to the job center and picking a new job. This ofcourse works like intended. But you can start a new bus route right after picking a new job at the business center. Maybe we should have the "new job objective" as a dominant objective so that you can not start anything job related whilst you have the objective for a new job.