It is part of the highway traffic act... right? : Nitrous oxide fuel systems prohibited - 172.1 (1) No person shall drive or permit to be driven on a highway a motor vehicle manufactured or modified after its manufacture such that nitrous oxide may be delivered into the fuel mixture unless, (a) the ...

It's clear that nitrous is illegal on highway roads. However we're still allowed to have it in the car just disconnected.

But can it be used in drag strip events or racing tracks?