Shadow on a surface... Help!!!

Hi,

I have some buildings on an uneven surface and would like them to cast shadows. My problem is that the shadows only get an outline. I have tried mesh but it doesn't work. 

I also have a problem with my roads. I would like to move them to my uneven surface, but I can only do this with project. If I do that it's again only the outline that shows.

Please help me.