Vehicles excluded from definition of " road vehicle "
1Any vehicle while it is not used on a public road and no vehicle excise licence is in force in respect of it.
2The following—
(a)any vehicle exempted from vehicle excise duty by section 4(1)(/j) of the [1971 c. 10.] Vehicles (Excise) Act 1971 (road construction vehicles) or section 7(1) of that Act (vehicles used only for passing to and from land in the same occupation);
(b)a vehicle of any of the following descriptions which is not chargeable with duty as a goods vehicle, namely an agricultural machine, digging machine, mobile crane, works truck, mowing machine or fisherman's tractor mentioned in Schedule 3 to that Act;
(c)a road roller.