The calculated route can be manually shaped to change its course. Adding a shaping point will allow you to customize the calculated route to take a certain road or through a certain area without adding a via point or destination to the route.

To manually shape the route:

Touch anywhere on the map when in an active route
Touch
Select a location on the map
- Allow the route time to calculate
Touch the map again to add another location
When you have finished shaping the route, touch Go!

This will shape the route to the way you want it to go. You can add up to 30 shaping points to your route. You can also save the changes to your route for future use by going into Trip Planner:

Press the Back arrow to return to the Where to? and View Map screen
Touch the apps icon
Touch Trip Planner
Touch Saved Trips
Touch My Active Route
Touch Save
Type the desired name for the route, then touch Done

The custom route will now be saved as a trip in Trip Planner.