NDrive expects some extra information in the kml file.
But here is one method:
- Find speedcameras for your country in the internet in TomTom ov2 format.
- Download and extract this NDrive speedcams importer from ervius (Thx to him!)
- Put the ov2 file into the pdi folder of the program
- Start the "Ndrive-speedcams-importer.exe"
- Select "Import .ov2" at the bottom. On the right side you should see your ov2 file now
- Select your ov2 file and hit the left arrow next to the "Fixed" field
- Now hit the "Create Database" button
- In the cams folder you will find the kml file now
- Copy the kml file to NDrive/speedcams and import it via the menu.