# To define the tunnel

To define a new tunnel, you can key in the definition or in the map select points, lines, arcs, or polylines in the job or in DXF, STR, SHP, or LandXML files and then create the tunnel from the selected items.

Once a tunnel is defined, you can edit it as required.

To key in the tunnel definition

1. Tap and select Define.

2. Tap New.

3. Enter a name for the tunnel.
4. To define a new tunnel from an existing tunnel definition, enable the Copy existing tunnel switch and then select the file to copy from. The file must be in the current project folder.

5. Select the method you will use to key in each component.

   1. To define the horizontal alignment you can use the:

      - Length or coordinate entry method
      - End station entry method
      - Points of intersection (PI) entry method
   2. Select the transition type. See Transition types.

   3. To define the vertical alignment you can use the:

      - Vertical points of intersection (VPI) entry method
      - Start and end point entry method

6. Tap Accept.

   The list of components that can be defined for the tunnel appears.

   To change the entry method or the transition type for the road, tap Options. However, once you have entered two or more elements defining the horizontal or vertical alignment definition, the entry method and transition type cannot be changed.

7. Select each component and define it as required.
8. To save your changes at any time, tap Store

To define the tunnel from the map

1. If the items you want to select are not visible in the map, tap in the map toolbar to open the Layer manager and select the Map files tab. Select the file and then make the appropriate layer(s) visible and selectable.

2. In the map, tap the items that will define the horizontal alignment.

   The order in which items are selected and the direction of the lines, arcs, or polylines defines the direction of the horizontal alignment.

   If the items have elevations, then the elevations are used to define the vertical alignment.

3. Tap and hold in the map and select Store tunnel.
4. Enter the tunnel name, start station, and station interval.

5. Tap OK.

   To add other components such as templates and set out positions to the new tunnel, tap and select Define. See To key in the tunnel definition.