A vehicle navigation system (100; FIG. 1) that includes a route calculation module (204; FIG. 2) that is operable to use marked diversions to avoid traffic events. The navigation system includes a simulation module (212) that is used to simulate traffic events that may occur along a route to a trip destination. A diversion module (214) is used to calculate a plurality of marked diversions that avoid the traffic events that may occur along the route. If a traffic event occurs along the route, the route calculation module only searches roads that contain a marked diversion to determine an alternative route around the traffic event.