Lights, wipers, glass and the walk-round

There are lights on your car you can't see from the driver's seat, and they're the ones other people depend on most. The brake lights and the rear indicators tell the driver behind what you're about to do; the number-plate lamp and the rear lights tell them you're there at all. National Highways, the government-owned company that runs England's motorways and major A-roads, puts it plainly: "If your indicators, hazard lights, headlights, fog lights, reverse lights or brake lights aren't working properly, you're putting yourself and others at risk." And, it adds, "They can be a reason for your vehicle to fail its MoT."¹ The windscreen (windshield in the US) and the wipers are the same bargain the other way round: they're how you see. This lesson is the walk-round that checks all of it, and the law in Great Britain that sits behind each item.

Several sections below state law, and each carries this label in short; here it is in full. This is general information, not legal advice. The rules differ between England and Wales, Scotland, Northern Ireland and each US state, and they change.

The walk-round

The practical part comes first, because the law makes more sense once you have stood behind your own car and looked.

The lights

National Highways gives the method, and it solves the problem in the first paragraph: "Ask a friend to help you, or park your vehicle near a reflective surface eg a window or garage door." Then, "In sequence, turn on your indicators, hazard lights, headlights and fog lights to check they're working", and "Press the brake pedal to check your brake lights, and finally select reverse to ensure your reverse light is working."¹

Nissan's handbook for the 2024 LEAF, sold in the US, covers the same ground in its own list and adds two things: "Clean the headlights on a regular basis. Make sure that the headlights, stop lights, taillights, turn signal lights, and other lights are all operating properly and installed securely. Also check headlight aim."² Aim is the one item on that list a walk-round can't settle. The MOT checks it in Great Britain, and lesson 21, "The MOT and Northern Ireland's vehicle test", covers the test.

Two lights are easy to forget. The number-plate lamp, which only comes on with the other lights and sits where you never look. And the reversing lamp, which needs reverse selected. Both precautions that follow are this course's own, not National Highways'. Select reverse only with the parking brake on and your foot held firmly on the brake, with any helper standing to the side of the car, never behind it. If that isn't possible, leave the reversing lamp for another day. And if the engine has to run for the lights to work, do this outdoors, never inside a garage, even with the door open. The Centers for Disease Control and Prevention (CDC), the US public-health agency, says: "Never run your car or truck inside a garage that is attached to a house, even with the garage door open."¹⁴ Its words are about a garage joined to a house; this course keeps a running engine out of every garage. Home Repair and Maintenance lesson 11, "Carbon monoxide and the alarms that warn you", explains why.

The Highway Code, which applies in Great Britain, adds that "lights, indicators, reflectors, and number plates MUST be kept clean and clear".³ That is a MUST, a legal requirement, and it is why the walk-round includes a cloth. In winter, lesson 15, "Winter and summer", takes up clearing snow and ice from them.

Glass

Look through the windscreen from the driver's seat, then walk round and look at it from outside, along the glass. You're looking for chips (small, roughly round pits) and cracks (lines), and for anything that blocks the view. Nissan's handbook says "Check the windshield at least every six months for cracks or other damage", and adds, "Have a damaged windshield repaired by a qualified repair facility."² Repairing glass is Call someone; finding the damage early, while it may still be a small repair, is Yours.

Nissan also gives a test for clean glass that needs nothing but a hose: "Your windshield is clean if beads do not form when rinsing with clear water."²

Wipers and blades

The RAC's winter checklist (the RAC sells breakdown cover and repairs), as the Met Office page reproduces it, says to "check your wipers are doing the job by spraying some washer fluid and checking they clean the windscreen", then run your fingers along the blades "to check for splits". It adds: "It's recommended to change wiper blades every 12 months."⁴ That is advice, not law, and it comes from that checklist, on a weather service's page.

Nissan's handbook ties the blades to how they work rather than to the calendar: "Check for cracks or wear if they do not wipe properly", and "Replace the wiper blades if they are worn." It also says what a worn blade does: "Worn windshield wiper blades can damage the windshield and impair driver vision."² Ford's handbook for the 2024 Maverick, sold in the US and Canada, answers the question "Why are there streaks and smears on the windshield?" the same way: "The wiper blades could be dirty, worn or damaged." Ford also gives a reason to spray before you wipe: "Do not operate the wipers on a dry windshield. This could scratch the glass or damage the wiper blades."⁵

Changing a blade is Yours, on conditions: where your handbook shows how for your car, and only by its method. Nissan's and Ford's handbooks each describe it for their own car, with steps that differ. This course doesn't generalise from them, and teaches nothing on the wiper arms themselves. Washer fluid was lesson 9's, "Under the bonnet: oil, coolant, brake fluid and screenwash".

The law on lamps, in Great Britain

This is general information, not legal advice.

On a Sunday afternoon in Welshpool, a neighbour helps with the walk-round and reports that the car's only number-plate lamp is out. Everything else works. The owner means to drive to work on Monday morning, in daylight, and home again after dark. Two questions: which rule reaches that lamp, and do the words of the daylight exception fit the plan? The rules follow; try to answer before the checkpoint below.

The rule is regulation 23 of the Road Vehicles Lighting Regulations 1989, which applies in England, Wales and Scotland. Regulation 23(1) says: "No person shall use, or cause or permit to be used, on a road a vehicle unless every lamp, reflector, rear marking and device to which this paragraph applies is in good working order and, in the case of a lamp, clean."⁶ It applies to two groups. The first is lamps a vehicle is required by the Regulations to have, and the list includes headlamps, front and rear position lamps (your handbook will show which switch position lights them), the rear registration plate lamp, the rear fog lamp, reflectors, daytime running lamps and the reversing lamp. The second is lamps it has, whether required or not, and that list includes "every" stop lamp (the brake lights), direction indicator, hazard warning signal device and front fog lamp "with which it is fitted".⁶ Which lamps your car is required to have is set elsewhere in the Regulations, which this course didn't read.

Then comes the exception people half-remember as "you're allowed a dead bulb in daylight". Regulation 23(3)(c) says the duty doesn't apply to "a defective lamp, reflector, dim-dip device or headlamp levelling device on a vehicle in use on a road between sunrise and sunset, if any such lamp, reflector or device became defective during the journey which is in progress or if arrangements have been made to remedy the defect with all reasonable expedition".⁶

Read the words slowly, because each one narrows it. It is only between sunrise and sunset. And it is only for a lamp that failed during the journey you are on, or one whose repair has already been arranged "with all reasonable expedition". The regulation doesn't list which lamps the exception covers; it says "a defective lamp". Nothing in it covers the trip home after dark.

The Highway Code adds two MUST lines from its Annex 6, citing the Lighting Regulations among other laws: the lights, indicators, reflectors and number plates must be kept clean and clear, and "lights MUST be properly adjusted to prevent dazzling other road users."³

What a dead lamp is at the MOT

The MOT, Great Britain's periodic test, is a separate thing from the duty above: the duty applies every time the car is used on a road, and the test is one day a year. DVSA's inspection manual for testers sorts lamp defects into its categories, and a Major one fails the test.⁷

Source: DVSA, MOT inspection manual, section 4, read 26 September 2026.⁷

So the Welshpool car, with its single plate lamp out, would fail. Lesson 21 covers the whole test and what Minor and Major mean for the certificate.

Northern Ireland has its own road traffic rules, which this course didn't read, and its own vehicle test, which lesson 21 covers.

The law on glass and wipers, in Great Britain

This is general information, not legal advice.

Two parts of the Road Vehicles (Construction and Use) Regulations 1986, which apply in England, Wales and Scotland, cover what you see through. Regulation 30 has two halves that are easy to run together. Its first paragraph is about how a car is built: it "shall be so designed and constructed" that the driver has a full view ahead. Its third is about upkeep: "All glass or other transparent material fitted to a motor vehicle shall be maintained in such condition that it does not obscure the vision of the driver while the vehicle is being driven on a road."⁸ The Highway Code's Annex 6 puts the same duty as a MUST: "windscreens and windows MUST be kept clean and free from obstructions to vision".³

For wipers, regulation 34 requires "one or more efficient automatic windscreen wipers" on a car with a windscreen, unless the driver can see ahead without looking through it, and lesson 9 quoted its paragraph (6): fitted wipers and washers are to be kept in efficient working order, and properly adjusted, at all times while the car is used on a road.⁹ Notice what it doesn't say. It sets no age for a blade. On this course's reading, a blade that clears the glass meets its words at two years old; one that smears doesn't at six months.

Window tints get two sentences in Annex 6: "You MUST NOT use a vehicle with excessively dark tinting applied to the windscreen, or to the glass in any front window to either side of the driver." And: "There are no VLT limits for rear windscreens or rear passenger windows."³ (VLT is visual light transmittance, how much light the glass lets through.) For the tint rule Annex 6 cites a regulation this course didn't read, so the lesson goes no further than those two sentences.

The windscreen at the MOT: zone A

This is general information, not legal advice.

At the MOT, the windscreen is judged by where the damage is as well as how big it is. DVSA's manual tells testers to check for "damage in windscreen zone A more than 10mm in diameter" and "damage in the remainder of the windscreen's swept area more than 40mm in diameter". Zone A is "in the swept area of the windscreen", "290mm wide" and "centred on the steering wheel".¹⁰

The drawing is this course's schematic of the manual's words, on a right-hand-drive car, and it isn't to scale: the manual gives zone A's width and says it sits in the swept area, and gives no height in words; its own drawing, linked below, shows the band running the full height of the swept area.

The figures are only half the rule. The manual goes on: "Failure for damage is only justified if the damage significantly affects the driver's view of the road." And a good repair isn't damage at all: "An 'invisible' or barely detectable repair, finished flush with the surrounding glass, does not count as damage."¹⁰ So the 10 and 40 mm figures tell the tester what to look at; whether it fails is a judgement about the view. If it doesn't, damage "not adversely affecting driver's view" is still recorded as a Minor defect in the manual's table, which doesn't fail the car.¹⁰

The wipers are in the same section. A "Wiper blade defective" is Minor; "Wiper blade missing or obviously not clearing the windscreen" is Major.¹⁰ Washers "not working or not providing sufficient fluid to clear the windscreen" are Major too.¹⁰

One chip, two inspections

A car has a chip 12 mm across in the glass, just to the right of the steering wheel's centre line, inside the area the wiper sweeps. At an MOT in Great Britain, that is inside zone A (it is within 145 mm of the wheel's centre, half of 290, which is this course's arithmetic) and over the 10 mm figure, so the tester looks at it, and it fails if it significantly affects the view. A repair finished flush with the glass would take it out of the question.

Now put the same car through a safety inspection in Poughkeepsie, New York. The state DMV's inspection page, as archived in July 2026, lists the windshield, to be checked "for presence and condition", and gives one rule with a number in it: "No crack of 11 inches long or longer is allowed if any part of the crack is within the area cleared by the windshield wiper."¹¹

In the US

This is general information, not legal advice.

There is no single US rule for lights and glass. Whether a car is inspected at all depends on the state, and lesson 22, "The US: state inspections, emissions tests and tread law", covers which states this course read. Among them, the lists look like this:

• New York (the DMV's inspection page, archived July 2026): lights including headlamps, tail lamps, stop lamps, directional signals, backup lights and "License plate lights"; the glass; the wipers ("check for presence and operation") and the blades ("check condition").¹¹ The page also states the duty behind the test: "Motor vehicles are required by law to be in safe operating condition whenever they are driven on a public street or roadway in New York State."¹¹
• Pennsylvania (PennDOT): the inspection covers "lighting and electrical systems, glazing (glass), mirrors, windshield washer, defroster, wipers", among other things.¹²
• Virginia (the State Police): the glass for "Cracked, scratched or broken glass", the wipers for "Condition of wiper blades", and the rear plate for "Illumination of rear plate".¹³

This course read no US state's statute on lamps or glass itself, only these inspection pages, and it gives no reason for the differences because no source it read gives one.

What people get wrong

"In daylight, a dead lamp doesn't matter." The daylight exception in regulation 23(3)(c) is narrower than that: a lamp that failed on the journey you are on, or whose repair is already arranged, and only between sunrise and sunset. The section on lamps above has the words.

"Washer fluid is optional." In Great Britain, fitted washers are to be kept in efficient working order at all times while the car is used on a road (regulation 34(6), lesson 9).

"A peephole in the ice will do." The Highway Code's rules on clearing glass before a winter drive are lesson 15's, "Winter and summer". The regulation above already says fitted glass must not obscure the driver's vision.

"Any chip fails the MOT." The manual's figures are 10 mm in zone A and 40 mm elsewhere in the swept area, and even then it fails only if the view is significantly affected; a flush repair doesn't count as damage.¹⁰

"You can see whether your brake lights work from the driver's seat." You can't. A helper, or a window or garage door behind the car, as National Highways says.¹

Practice

For your plan

This lesson adds the walk-round to your car file's checks log: lights front and rear, plates, glass and wipers, with the date and anything found. Beside it, from your handbook: which bulbs or lamps it shows you how to change, if any, and how it describes changing a wiper blade. Pair the walk-round with lesson 9's under-bonnet check and you have the owner's routine; how often is your choice, and the Highway Code's advice is to check the fluid levels at least weekly.

Connections

Lesson 1, "What a car is made of, and why the handbook comes first", taught the difference between the Highway Code's MUST and its should, and this lesson used both. Lesson 9, "Under the bonnet: oil, coolant, brake fluid and screenwash", covered the washer fluid and regulation 34(6). Lesson 15, "Winter and summer", takes up clearing glass and lights in snow and ice; lesson 20, "The law on a car's condition: Great Britain and Northern Ireland", what can follow from a defect on the road; lesson 21, "The MOT and Northern Ireland's vehicle test", the whole test; and lesson 22, "The US: state inspections, emissions tests and tread law", the US states.

Go deeper

• DVSA, "MOT inspection manual", section 3, "Visibility" and section 4, "Lamps, reflectors and electrical equipment", free. Read here in full. What a tester in Great Britain actually looks at, with the manual's own zone A drawing.
• The Road Vehicles Lighting Regulations 1989, regulation 23, free. Read here in full. Short, and worth reading in its own words rather than as it's repeated.
• National Highways, "How to check your vehicle", free. Read here in full. The official checklist, lights included.
• Your own handbook, the lights, wipers and "do-it-yourself" sections: which lamps and blades it lets you change, and how.

Sources

1. National Highways, "How to check your vehicle", undated. The government-owned company that runs England's motorways and major A-roads. Read: full text, re-read 26 September 2026.
2. Nissan North America, 2024 LEAF Owner's Manual and Maintenance Information (US market), PDF. Read for this lesson, 26 September 2026: pp. 8-11 to 8-12 (wiper blades) and 9-2 to 9-4 (owner checks), in full. A maker's handbook for its own car.
3. The Highway Code (Department for Transport and DVSA), "Annex 6. Vehicle maintenance, safety and security", updated 29 January 2022. Great Britain. Read: full text, re-read 26 September 2026 through the GOV.UK content API.
4. Met Office, "6 simple checks to prepare your vehicle for winter", undated. The UK's national weather service; the page reproduces the RAC's winter checklist. Read: full text, re-read 26 September 2026.
5. Ford Motor Company, 2024 Maverick Owner's Manual, edition 202307, US and Canada, read from Internet Archive capture 20250505042038. Read for this lesson, 26 September 2026: printed pages 88 to 91 (wipers and washers). A maker's handbook for its own truck.
6. The Road Vehicles Lighting Regulations 1989 (SI 1989/1796), regulation 23, as amended. England, Wales and Scotland. Read: the whole regulation on the live page, 26 September 2026. The regulations that say which lamps a car must have were not read.
7. Driver and Vehicle Standards Agency, "MOT inspection manual: cars and passenger vehicles", section 4, "Lamps, reflectors and electrical equipment", section updated 2 April 2024, manual updated 1 June 2026. England, Scotland and Wales; written for testers. Read: section 4 in full, with 4.1.1, 4.3.1, 4.4.1 and 4.7 closely, 26 September 2026.
8. The Road Vehicles (Construction and Use) Regulations 1986 (SI 1986/1078), regulation 30, as amended. England, Wales and Scotland. Read: the whole regulation on the live page, 26 September 2026.
9. The Road Vehicles (Construction and Use) Regulations 1986, regulation 34, as above. Read: the whole regulation on the live page, 26 September 2026.
10. Driver and Vehicle Standards Agency, "MOT inspection manual", section 3, "Visibility", section updated 29 November 2024, manual updated 1 June 2026. England, Scotland and Wales. Read: section 3 in full, 26 September 2026.
11. New York State DMV, "New York State Vehicle Safety/Emissions Inspection Program", read from Internet Archive capture 20260710141515 (the DMV's site refuses automated readers). Read: the page in full, 26 September 2026. The live page is linked for the reader.
12. Pennsylvania Department of Transportation, "Safety Inspection Program Frequently Asked Questions for Consumers", undated. Read: the list of items inspected on passenger cars, re-read 26 September 2026.
13. Virginia State Police, "Vehicle Safety Inspection", undated. Read: the web page in full, re-read 26 September 2026.
14. Centers for Disease Control and Prevention, "Carbon Monoxide Poisoning Basics", 12 January 2026, read from Internet Archive capture 20260920191925 (the live page refuses automated readers). US. Read for this lesson: the page's car and truck prevention lines, 26 September 2026. The live page is linked for the reader.