A track assembly is to be mounted on a drive axle of a vehicle. The track assembly has a frame, at least one leading idler wheel mounted to the front of the frame for rotation about a transverse leading idler wheel axis, at least one trailing idler wheel mounted to the rear of the frame for rotation about a traverse trailing idler wheel axis parallel to the leading idler wheel axis, a single drive wheel assembly, and at least two slide rails. The slide rails have corresponding forward-facing portions, central portions, and rearward-facing portions. The forward-facing portions project from the front ends of the central portions by a projection that is greater than a length of the central portions. A vehicle having the track assembly is also described.