(1) A person shall not drive a mechanically propelled vehicle or a powered personal transporter at a speed exceeding the speed limit -
(a) that applies in respect of that vehicle or transporter, as the case may be, or
(b) that applies to the road on which the vehicle or transporter is being driven where that speed limit is lower than that applying to that vehicle, or transporter, as the case may be.
(2) A person who contravenes subsection (1) is guilty of an offence.
(2A) In a prosecution for an offence under this section, it is presumed, until the contrary is shown by the defendant, that the speed limit indicated on a traffic sign is the speed limit that applied under this Act to the road when the offence is alleged to have been committed.
(3) In this section "speed limit" means a limit which is- (a) an ordinary speed limit, (b) the built-up area speed limit, (c) the regional and local roads speed limit, (d) the national roads speed limit, (e) the motorway speed limit,
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