Route Calculation

After entering the destination the route is always calculated and updated in the COMAND operating, display and control module (A40/3) by the navigation processor (A40/3n2). It can only be calculated within the digitalized map area. Calculation of the route is the prerequisite for the guidance feature.

Route calculation
The navigation processor (A40/3n2) calculates the route with the aid of the CD-ROM map data, the destination entered and the momentary position. When calculating it considers attributes read from the CD-ROM map such as one-way streets, turn prohibitions, street classifications, etc. (if present). This allows the driver to determine the way the route should be calculated:
- Quickest route
- Shortest route
- Dynamic route (only with code 815, in (USA) not as of introduction of COMAND system)
- Own selection

When "Dynamic guidance" is selected (only with code 815, in USA not as of introduction of COMAND system) traffic information received via radio (FM/RDS or cellular telephone) is stored with the aid of the traffic data memory (A2/43) and is considered automatically when calculating the route. The route is then time- optimized similar to the option "quickest route". A message appears that the route has been recalculated using the information from the traffic messages. Presently the "dynamic guidance" feature is only used for freeways.

With the function "Own selection" the following route sections can be excluded from the route calculation:

- FREEWAYS, FERRIES, TOLL ROADS

Following route calculation the navigation processor (A40/3n2) makes up a list of the streets and intersections along the route This route list is used for guidance. It can be displayed with the menu "Info".

Route updating
If the driver deviates from the calculated route, the navigation processor (A40/3n2) calculates a new route list. The current position and the driving direction are considered and the new route is optimized correspondingly. The message "New route" appears on the display.

Driving outside of digitalized map area
If the vehicle leaves the digitalized CD-ROM map area (e.g. driving in a parking building) it is not possible to calculate or update a route. "OFF ROAD" then appears on the display. When the vehicle is outside of the map boundaries (e.g. driving in foreign country) "NO MAP" appears on the display. Destinations outside of the digitalized map area cannot be considered when calculating the route.

Driving around traffic jams with the function button "Detour"
When a traffic jam is announced by the traffic station a route which avoids driving through the traffic jam can be calculated before reaching the affected section. For this purpose press the "Detour" button ((USA): "DETR" button) and do one of the two following:
- Enter length of traffic jam including the distance to the start of the traffic jam or
- Delete the corresponding road section in the detailed route list.

The "Detour" function is also available for federal highways and state highways as well as streets in the city.