Jagged usually refers to your screen resolution being low and not anti-aliased... that's when you get 'jaggies', but I wouldn't know what they would mean with 'textures are jagged'. There aren't literally pixels visible in your textures right?

A wait, I just looked at the textures again and I think they are referring to how every texture looks pretty sharp and rough with points in them. On your road texture for example you can see quite sharp points, that does indeed look 'jagged',

Cheers