This package contains low poly models that are very optimized assets. I already created a Two sample scene with proper light mapping Day and night mode.
Create your own Race Track using this assets package.

This package contains including:
Farm Bike one FBX file with two different color textures. (Tris :2828).
Four advertising boards.
State road 3 different scales, Lift and right turns, U-turn Road checks.
Tires, Drum, Lights and speakers.
Total assets Tris:3767

Each object has individual prefabs with a collider.