I found some interesting sites with free textures.
Might be useful for the track as a good base to build own textures
http://www.textureking.com/index.php/category/concrete
http://mayang.com/textures/Architectural/html/Brick/index.html
http://www.cgtextures.com/
http://freestocktextures.com/
Might be useful for the track as a good base to build own textures
http://www.textureking.com/index.php/category/concrete
http://mayang.com/textures/Architectural/html/Brick/index.html
http://www.cgtextures.com/
http://freestocktextures.com/