People should be able to download the resultant file and put it in their mods/levels folder to some appreciable degree of success. *To make your file work for those who download it, in zip form (as the forums do require now), when you're in your beamng.drive folder in my documents, browse to levels, select your level's directory and right click, now choose SEND TO: Compressed File and let the computer do the rest. Your shadows will work well and the edges won't have strange glitches. Copy the /roads directory out of my map and edit the materials.cs to reference YOUR map directory with something such as notepad++ which makes replacing things in bulk like path names super-easy. *If you need textures for roads with and without transparency, steal them out of Nevada Interstate or So-Cal Interstate maps, I made the textures for the asphalt roads, feel free to use them, (NT and NOTRANS named textures have No Transparency and can be used on MESH roads). *Use a break-angle of 0.5 or 1.0 if you want a smoother change to the taper of the mesh roads, many folks miss this (it is easy to miss!).

*Drop you mesh roads into the surface of the land just a bit and use the smoother or lower land tool to lower the land just below the road surface so that it is possible to get back on the road if you slide off. *Use a texture length of 15~20 or so, so it looks proportionate and doesn't repeat every 6 feet. *Use textures with transparency=0 on mesh roads, so that shadows and such work properly and the texture edges don't glitch.

Looks like you've gotten into level editing here on beamng.drive - fun fun fun! Just a few tips:

Akina mod for beamng drive