A square white sign shows a farm tractor inside a red ring with a diagonal line through it. Where would you expect to see it, and who is it aimed at?

Correct answer: A. On freeways and roads posted at 90 km/h or more — the tractor symbol stands for all farm vehicles

On fast roads, and at farm vehicles generally. Book 5 says the NO TRACTORS sign "is used to indicate the prohibition of tractors and other farm vehicles from travelling on designated sections of freeways and roads with posted speed 90 km/h or more," and that "the intent of the sign is to keep slow-moving vehicles off high speed freeways and roads, where they present a hazard to other road traffic, as well as to the farm vehicles themselves." Note the reach of the symbol: "while the sign may refer to other farm vehicles than tractors, the tractor symbol must be used to represent all types of farm vehicles." So the picture is a tractor, but the rule covers combines, farm wagons and the rest.

Source: MTO Driver's Handbook: Ontario Traffic Manual, Book 5 — Regulatory Signs (December 2021), Section 15.5 — NO TRACTORS Sign (Rb-60)