I'd recommend you look on the HMRC website when your running a tractor, they have lots of guidelines on Red, and it's worth knowing what you can do on it, for instance you cannot tow a trailer for haulage of goods on it, this was used around our area to stop JCB fastracs hauling stone around and putting lorries out of business, they were also over the 24 ish tonne Gross vehicle train weight for tractors and trailers, so it stopped pretty quickly.