The powers library38 of 59 Road policing

Power to stop vehicles

s.163Road Traffic Act 1988

Lets a constable in uniform require the driver of any mechanically propelled vehicle, or the rider of a cycle, on a road to stop, without needing any suspicion.

Power to stop vehicles · Road Traffic Act 1988, s.163Card 38 / 59

When you can use it

s.163(1)The person is driving a mechanically propelled vehicle, or (s.163(2)) riding a cycle
The vehicle or cycle is on a road
The requirement to stop is made by a constable in uniform, or by a traffic officer
No grounds, belief or suspicion are needed, but the stop must be for a genuine policing purpose, not oppressive or capricious
Traffic officersOnly in uniform, and only for traffic management purposes, on roads within their jurisdiction or where acting at police direction or with the traffic authority's consent (Traffic Management Act 2004, s.5)

What it allows

Requiring a driver or cyclist on a road to stop. Random stops are lawful (Chief Constable of Gwent v Dash 1986).
Keeping the vehicle stopped long enough to make lawful enquiries, such as checking documents. Failing to stop long enough for those enquiries is recognised in s.165A(4)(b).
It is the stopping power used for road checks under PACE s.4.
It gives no power to search the vehicle or its occupants, and no power of entry to private land.

Key definitions

Mechanically propelled vehicle – not defined in the Act. It is wider than “motor vehicle” (s.185), which also requires the vehicle to be intended or adapted for use on roads.
Cycle – s.192: a bicycle, tricycle or cycle with four or more wheels, not being a motor vehicle.
Road – s.192: any highway and any other road to which the public has access, including bridges.
In uniform – the officer must be readily identifiable as a police officer. A plain-clothes officer cannot use this power.

Safeguards

PACE Code A covers search powers, not the s.163 stop itself. If the officer then searches the person or vehicle, a separate power is needed and Code A applies in full.
There is no power to stop or detain a person in order to find grounds for a search (Code A, para 2.11).
Stops must not be discriminatory: the Equality Act 2010 applies to how the power is used.

Good to know

Failing to stop is an offence (s.163(3)). It is summary only: a level 5 fine for a mechanically propelled vehicle, level 3 for a cycle.
After the stop, related powers include s.164 (driving licence), s.165 (insurance, MOT and name and address) and s.6 (preliminary breath test).
The power applies to the driver or rider only, not to passengers or pedestrians.

Legislation: Road Traffic Act 1988, s.163 (opens legislation.gov.uk in a new tab)
Who can use it: A constable in uniform, or a traffic officer in uniform
Last checked: 3 November 2026, against the current law on legislation.gov.uk

Power to stop vehicles: questions people ask

When can the police use power to stop vehicles?

1. The person is driving a mechanically propelled vehicle, or (s.163(2)) riding a cycle 2. The vehicle or cycle is on a road 3. The requirement to stop is made by a constable in uniform, or by a traffic officer 4. No grounds, belief or suspicion are needed, but the stop must be for a genuine policing purpose, not oppressive or capricious 5. Only in uniform, and only for traffic management purposes, on roads within their jurisdiction or where acting at police direction or with the traffic authority's consent (Traffic Management Act 2004, s.5)

Who can use power to stop vehicles?

A constable in uniform, or a traffic officer in uniform.

What law gives the power for power to stop vehicles?

Road Traffic Act 1988, s.163.

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