Need to project mesh of the road onto landscape that is not flat
Tried Shrinkwrap modifier and the result is as on the 2nd screenshot
If nothing works, how can i just draw the road on the landscape with a brush?
Shrinkwrap with a Solidify modifier below seems like a good solution, but you need no subdivide your road a bit:
I suggest using Knife Project as it gives the desired result and is fastest. Use it and give the highlighted faces a new material then delete the mesh you projected. Shrinkwrap is, too, about shrinking which, in your case, is not needed. Is it OK?
The simplest way I can think of, is extruding both the floor and the road along the z-Axis and using the boolean modifier in order to copy the environment's surface to the road. You might have z-fighting, so I recommend to move the road slightly up.