Optional flashing indicators - Legal Requirements (UK)
(Direction indicators; Rear retro-reflectors and Rear fog lamp)

Warning: this article is advisory and not a definitive statement of current UK law  – you are responsible for making a check yourself.  Reference must be made to both the MoT Inspection Manual and The Road Vehicles Lighting Regulations1989.

This article was prepared for UK owners of pre-war Austin Sevens but may also be relevant to owners
of pre-1950s historic cars which we not originally fitted with flashing indicators when manaufactured.

Semaphore indicators were fitted to pre-war vehicles, and showed an amber coloured light when seen from both front and rear. It was an innovation when flashing indicators, then coloquially referred to as 'winkers', first appeared on British cars in the early 1950s, introduced from America where they were already in common use.  They were operated through the front and rear sidelights thereby showing a flashing white light to the front and a flashing red light to the rear, therefore, not clearly seen and their use not easily recognised.  The fitting of flashing indicators at manufacture was not covered by the UK Vehicle (Construction & Use) and the Road Vehicle Lighting Regulations applicable at that time.

It wasn't until May1956 that the legislation was amended to allow for the fitting and use of flashing indicators for new cars registered after the end of 1958.  The new regulation stated that: "The three new standards to be enforced will be: direction indicators should be amber in colour; they should neither exceed nor fall below a certain standard of brightness, and if they are of the fore and aft flashing type they should be quite separate from other lights."

Where to start
Like most drivers of ‘Sevens’ I recognised that modern, high speed, motorists are not used to slow historic vehicles with semaphore signalling or the use of hand-signals, so I investigated the legal aspects of fitting flashing indicators, rear reflectors and a rear fog lamp, to my Big Seven.  The specific information required was on minimum and maximum distances from the sides of the car and height from the ground, but other information would be useful.  

Confusion arises for owners of pre-war vehicles because sources state that for vehicles first used before 1 September 1965 direction indicators may be incorporated with stop lamps, or combined with side or rear lamps.  This actually means that they can be fitted in a cluster of lights, generally at the front and rear corners.

As flashing indicators had never been fitted to pre-war and immediate post-war vehicles, nor deemed to be legal, prior to the 1956 amendment of the Regulations it is not possible to justify that they could be retro-fitted to vehicles of those eras.  This was confirmed when seeking information as I was advised that if flashing indicators were not original equipment when the vehicle was built, and are now being fitted by choice of the owner/driver, then they are an optional fitting and have to comply with current legislation and not to try and rely on retrospective legislation, which has since been superceeded, or did not apply at the time of vehicle manufacture.

Now that vehicles manufactured pre-1960 are no longer subject to a compulsory annual (UK) MoT test any optional lighting once fitted will still be part of a voluntary MoT test and must work, there being a few exceptions.  The MoT Inspection Manual is relevant and can be viewed at www.ukmot.com/1-5.asp#Text_top 

Direction indicators and hazard warning devices
The legal requirements relating to obligatory direction indicators and to optional direction indicators is covered by The Road Vehicles Lighting Regulations1989, Statutory Instrument 1989 No.1796.  Schedule 7 Part I: Requirements relating to obligatory direction indicators and to optional direction indicators to the extent specified in part ii.  It can be viewed in full at www.legislation.gov.uk/uksi/1989/1796/contents/made.

The SI states at Para 7. Colour [of indicator lamp] (a) Any vehicle not covered by sub-paragraph (b): Amber.  Then at [sub-para] (b) An indicator fitted to a motor vehicle first used before 1st September 1965 – (i) if it shows only the front: white or amber (ii) if it shows only the rear: red or amber (iii) if it shows both to the front and to the rear: amber. 

The position of indicators is given in Para 2 (b).  For a vehicle first used before 1 April 1986 there is no maximum lateral distance from the side of the vehicle but the 400mm required on newer cars is a sensible distance. There is no maximum height above the ground, but the minimum height is 350mm.  The wattage must be between 15 and 36 watts, with no requirement on light intensity [Para (8)].  A rear direction indicator on each side of the vehicle shall not be fitted on a boot lid or other moveable part of the vehicle.  

The regulations also consider the angles of visibility and of relevance to pre-war Austin Sevens and similar cars, the Statutory Instrument states at:

Para 1 (d) For a motor vehicle first used on or after 1st January 1936 and before 1st April 1986: Any arrangement of indicators so as to satisfy the requirements for angles of visibility in paragraph 3.  Then in Para 3 Angles of Visibility at (b) A motor vehicle first used before 1st April 1986: Such that at least one (but not necessarily the same) indicator on each side is plainly visible both to the front and rear in the case of any vehicle.

Para 1 (e) For a motor vehicle first used before 1st April 1936: Any arrangement of indicators so as to make the intention of the driver clear to other road users.  

The indicators on one side of the vehicle shall be operated by one switch [Para 10 (a)] and shall flash in phase constantly at a rate of not less than 60, nor more than 120, flashes per minute [Para 12 (a)].  It may be necessary to run the engine when checking the flashing rate.  Every indicator shall when in operation perform efficiently regardless of the speed of the vehicle.

A rear direction indicator on each side of a vehicle shall not be fitted on a boot lid or other movable part of the vehicle [Para 12 (c)].

The regulation does not mention a self-cancelling switch so, by omission, it is not required.  If one is fitted, now the norm on modern cars, it is not tested. 

A driver's 'tell-tale' warning device for the indicators in operation must be fitted and can be audible or visual [Para 11(a)].  It is not required if one or more of the indicators on each side can be seen by the driver from the driver's seat, which is unlikely if lights are fitted at the front and rear of the vehicle.  So fit a 'tell-tale' on the dashboard. 

If a hazard warning device is fitted it must be operated by only one switch whether the ignition is on or off.  The indicators must flash simultaneously and the 'tell-tale' must work correctly.  The hazard 'tell-tale' may be the same as the indicator 'tell-tale' or a separate light, but it must be a flashing light.  If any indicator or 'tell-tale' bulb is not functioning that is sufficient reason to fail the MoT test. 

Rear retro-reflectors
These are covered by The Road Vehicles Lighting Regulations 1989 No. 1796 Schedule 18 Part I Requirements relating to obligatory rear retro reflectors and optional rear retro reflectors to the extent specified in part ii.

The number required is two, each to be a minimum lateral distance from the side of the vehicle of 610mm for a vehicle first used before 1 April 1986 [Para 2 (A) 4], but there is no minimum separation distance between the pair, nor is there a minimum height above the ground, although the maximum height is 1525mm [Para 2 B (2)(c)(i)(B)].  A rear retro-reflector shall not be fitted on a boot lid or other moveable part of the vehicle [Para 8 (c)].  Reflective tape is not accepted as a substitute for a rear retro-reflector. 

Rear fog lamp
This is covered by The Road Vehicles Lighting Regulations 1989  No. 1796  Schedule 11  Part I Requirements relating to obligatory rear fog lamps and to optional rear fog lamps to the extent specified in part ii.

Only one need be fitted, either on the centre-line, or to the off-side, of the vehicle [Para 2 (b)]. If a symmetrical pair of lamps is fitted, only the centre or off-side one will be tested. The minimum height above the ground is 250mm [Para 2 (c) ii] and the maximum 1000mm [Para 2 (c) i]  A minimum separation distance between a rear fog lamp and a stop lamp is 100mm [Para 2 (B) d]. 

The colour must be red [Para 7], but there is no requirement as to the size of the illuminated area [Para 6], the wattage [Para 8] or intensity [Para 9].  A rear fog lamp must be wired so that it will only work when the headlamps are in use and must not be operated by the braking system [Para 10].  A closed-circuit 'tell-tale' must be fitted on the dashboard. [Para 11] 

Materials and equipment
Flashing lights of the style fitted to motorcycles, available from any motorcycle shop or Vehicle Wiring Products are suitable.  Holden Vintage & Classic and Auto Electric Supplies, seem to be the only suppliers of 6v 36w flasher units, otherwise use 2 x 18w motorcycle units.  It is easy to fit the wire through flexible slit convoluted tubing to protect it under the car.

opflash web

I cut and drilled short lengths of 25mm x 5mm mild steel to fit short bars above and under the bumper irons, filing the irons and bars to make the earth contact.  These fit neatly behind the bumpers and are held with an M8 x 55mm bolt.  The wiring in the convoluted tubing followed the chassis member on the offside to the rear and along the main wiring loom, all fixed with cable ties.  Wiring to the front indicators went through the engine compartment to the chassis members and the bumper irons.  The only 'modification' to the car was a small hole in the bulkhead to take a self-tapping screw to fix a cable tie base to mount the flasher unit.  The whole lot can be removed from the car within 10 minutes if someone wishes to return it to original specification.  For that reason I have retained the semaphore system separate from the flashing indicators.

Whilst taking the wiring to the rear offside I included wiring for a rear fog lamp.  I have also fitted a symmetrical pair of red retro-reflectors.  The car had already been fitted with obligatory stop/tail lights and reflectors in the 1950's to comply with legislation for a car built after 1 January 1936. 

Before I even took the car on the road I felt a lot happier having the use of flashing indicators.


This article, written by Doug Castle, originally appeared in CA7C Seven Focus in Mar 2004 pp21-23.  Edited for clarity in May 2013 and January 2023.

When I decided to fit flashers and a rear fog lamp to my Big Seven and to write this article I sought information from the Bedfordshire Police, a registered MoT Tester, the relevant documents for the MoT Tester's manual, and current legislation as cited above.  Also: From the archive, 17 May 1956: New rules for "winkers" | Transport policy | The Guardian


See also:

'Fitting Flashers - but keeping the Semaphore Signals