Draw a straight line on landscape

Hi guys,

I’ve got a problem to draw a straight line in landscape mode. I have to paint a lot of straight lines in a some kind of road (a lot of linemarks). The best solution for me will be using a spline to “show” a texture how I would like to paint it and project texture to the landscape (same solution what you can find in substance painter now). Did you know something about plugin or solution in this case?

Thanks!