Extracting roads from a DTM

[DominicHsiao]

We are trying to detect roads in DTM, one thing we have done is created a slope map which clearly defines roads. However, there is a lot of noise due to the tops of the mountains and ridges which are flat. Is there a way to filter out the noise, i.e. the mountain tops. Or is there a completely different solution that we should look into to? We don't want to use satellite imagery, because it doesn't match our DTM. Eventually, we want to use this as a mask for roads. This will be done by inverting the colors. However, when that is done the noise is really prevalent. 

This is the slope map, the main noise is coming from lower-middle section on the left side. 

 Inverted slope map with modified exposure setting to try to drown out the noise

[Taren_Esri]

Hi @DominicHsiao 

I was able to find an existing discussion on this topic here. Hopefully it is of some help!

Best,

Taren

[DominicHsiao]

Thanks! Really appreciate it.