GTA SA mountain

Hi! I would like to build a little mountain, on which to put a two-lane street and the street to have serpentines, uphills, downhills, a lot of turns... The street should go from the base of the mountain to the top of it. On the top I will make some things. I tried to make a long plane, for example 10 by 1000 and then make a line and curved it using fillet. Next, I applied the Path Deform modifier to the plane. Then I should...surrender that road into the mountain. But I do not know how. I will make some things at the top, but can you give me some tips for making a little mountain and a realistic road on it for GTA SA? I can post some pictures of a mod that has some of the things I said. Pease help me!!! Thank you very much and have a nice day!