Most "more traffic" mods destroy your CPU. The 2Real engine uses instanced rendering and LOD (Level of Detail) optimization. You get 3x the cars at the same frame rate as the old 1.0 version.
The only problem? The base tool usually ships with placeholder vehicles or just two or three generic car models. Seeing the same blue sedan repeat every four seconds destroys the illusion of reality. This gap is exactly what was designed to fill. 2real - more traffic cars for traffic tool 1.0