Grass On Roads

Hello! I've been working in the editor to make a map. I am using the road editor and notice that the terrain's grass is still peaking through, and the driving material is still grassy so cars have no traction on it. How can I fix this?

Thanks!

 

in the material's editor (i think thats what it's called) you need to create a material using a pre-existing texture that will function as asphalt.