Split track for various materials, different road surfaces

[abrimaal]

I want to make the selected part a ground road. Now the whole road is tarmac.
How to do it in BobsTrackBuilder?

I can simply split it in 3dSimEd, but this track will be edited in BTB not once.

 

[Mangoletsi]

Brendon Hartley made youtube videos how Bob's Track builder works 15 years ago

https://www.youtube.com/user/Piddy555/videos