UK driving offences you might not know about

A handful of common driving habits are technically offences — most of them under the Road Traffic Act 1988, the Highway Code, or the Construction and Use Regulations 1986. They tend not to be top-of-mind for learners (or for many qualified drivers), but they show up on the theory test, at the roadside, and on insurance claims. Ten of the ones that catch people out, with the rule or statute behind each and the typical penalty.

Many of the rules in the Code are legal requirements, and if you disobey these rules you are committing a criminal offence.

1. Sounding your horn at night in a built-up area

The law: Highway Code Rule 112 prohibits using your horn in two situations: while stationary on the road, and when driving in a built-up area between 11.30 pm and 7.00 am — except in both cases when another road user poses a danger. Statutory basis: the Construction and Use Regulations 1986, regulation 99.

Penalty: typically a £30 fixed penalty notice, rising to a maximum of £1,000 if contested unsuccessfully at court. Aggressive horn use is also captured by the wider careless driving offence (see #3).

2. Hogging the middle lane on the motorway

The law: Highway Code Rule 264 — "Keep in the left lane unless overtaking". Section 3 of the Road Traffic Act 1988 — driving without reasonable consideration for other road users. Since 16 August 2013, police can issue fixed-penalty notices for careless driving offences including middle-lane hogging, tailgating, and undertaking.

Penalty: £100 fixed-penalty notice and 3 points (endorsement code CD10), or an unlimited fine and 3–9 points at court for the substantive careless-driving offence (level 5 on the standard scale, which has been unlimited since 12 March 2015).

3. Splashing pedestrians on a wet day

The law: Section 3 of the Road Traffic Act 1988 — "driving a mechanically propelled vehicle on a road or other public place without due care and attention, or without reasonable consideration for other persons using the road or place". Splashing pedestrians by driving through a puddle close to the pavement falls under "without reasonable consideration".

Penalty: typically a £100 fixed-penalty notice and 3 points (CD10) at the roadside, or an unlimited fine and 3–9 points at court if contested.

4. Touching your phone at a red light

The law: from 25 March 2022, the Road Vehicles (Construction and Use) (Amendment) (No. 2) Regulations 2022 (SI 2022/81) tightened the existing hand-held mobile phone rule (regulation 110 of the Construction and Use Regulations 1986). The amended rule prohibits any use of a hand-held phone, tablet or device while driving — photo, video, navigation, scrolling, checking notifications, unlocking — including while stopped at traffic lights or in stationary traffic with the engine running . The narrow exception is a contactless payment at a drive-through or toll while the vehicle is stationary. Picking up the phone to skip a song still counts as an offence.

Penalty: 6 points and a £200 fixed-penalty notice (endorsement code CU80), or up to £1,000 and a possible disqualification at court. For drivers in their first 2 years after passing the test, this single offence triggers automatic revocation under the New Drivers Act.

5. Smoking in a car with anyone under 18 present

The law: each UK nation has its own statutory instrument with its own commencement date. In England, the Smoke-free (Private Vehicles) Regulations 2015 (SI 2015/286) came into force on 1 October 2015. Wales adopted the equivalent rule on the same date via the Smoke-free Premises etc. (Wales) (Amendment) Regulations 2015 (WSI 2015/1363). Scotland followed on 5 December 2016 (the Smoking Prohibition (Children in Motor Vehicles) (Scotland) Act 2016). Northern Ireland commenced on 1 February 2022 (the Smoke-Free (Private Vehicles) Regulations (Northern Ireland) 2021, SR 2021/328). In every nation, it is an offence to smoke in any enclosed private vehicle carrying someone under 18, even with the windows open.

Penalty: in England, Wales and Northern Ireland — £50 fixed-penalty notice for the smoker, and a separate £50 fixed penalty for the driver who fails to prevent smoking. In Scotland — £100 fixed-penalty notice, with a fine up to £1,000 (level 3 on the standard scale) on summary conviction.

6. Sleeping in your car while over the drink-drive limit

The law: Section 5(1)(b) of the Road Traffic Act 1988 — "being in charge of a motor vehicle on a road or other public place" while over the prescribed alcohol limit. "Being in charge" has been interpreted broadly by the courts: sleeping in the driver's seat with the keys in the ignition can qualify; sleeping in the back seat with the keys out of reach is harder for the prosecution to make stick. The legal limit is 80mg / 100ml of blood in England, Wales and Northern Ireland, and 50mg / 100ml in Scotland.

Penalty: up to 10 penalty points, 3 months' imprisonment, a £2,500 fine and discretionary disqualification. Lower than the "driving while over the limit" offence under section 5(1)(a), but still substantial.

7. Driving with snow or ice on the roof or windscreen

The law: Highway Code Rule 229 — "you MUST be able to see, so clear all snow and ice from all your windows". Statutory basis: regulation 30 (windscreens, glass and mirrors) and regulation 100 (maintenance and use of vehicle so as not to be dangerous, etc) of the Construction and Use Regulations 1986. Section 42 of the Road Traffic Act 1988 makes contravening these "other" C&U requirements an offence (section 41A handles only brakes, steering-gear and tyres; section 42 picks up the rest). Snow flying off the roof and obscuring the vision of the driver behind is also captured by section 3 (careless driving).

Penalty: typically a £60 fixed-penalty notice and 3 points, with the careless driving route available if the snow causes actual danger.

8. Lending your car to someone who isn't insured to drive it

The law: Section 143 of the Road Traffic Act 1988. Subsection 143(1)(a) prohibits using a vehicle without insurance; subsection 143(1)(b) prohibits causing or permitting another person to use it without insurance; subsection 143(2) makes a contravention of either an offence. Both offences carry the same maximum penalty. A casual "borrow my car for an hour" to a friend or family member who is not named on your policy and does not have their own cover is enough to trigger this.

Penalty: £300 fixed-penalty notice and 6 points (endorsement code IN10) at the roadside; up to an unlimited fine and discretionary disqualification at court. The vehicle can be seized and crushed under section 165A of the Road Traffic Act 1988.

9. Driving without your prescribed glasses or contact lenses

The law: Section 96 of the Road Traffic Act 1988 makes it an offence to drive with eyesight that fails the prescribed standard — and if your licence requires corrective lenses, driving without them is the most common way of falling foul of it (endorsement code MS70). The underlying eyesight standard is the 20-metre number-plate test (Highway Code Rule 92) — you must be able to read a vehicle number plate from 20 metres in good daylight.

Penalty: 3 penalty points and a fine of up to £1,000 (endorsement code MS70). DVSA / police can also revoke the licence on medical grounds if the eyesight test fails at the roadside. See our mnemonics guide for the 20-metre rule.

10. Flashing your headlights to warn of a speed camera or speed trap

The law: Section 89(2) of the Police Act 1996 — wilfully resisting or obstructing a constable in the execution of their duty. Prosecutions for warning other drivers of a speed trap are difficult to secure: the prosecution must show that flashing was a deliberate, wilful obstruction of a specific officer carrying out a specific duty, not merely a courteous gesture. But it is technically an offence and prosecutions have occasionally succeeded. Highway Code Rule 110 separately discourages flashing headlights for any reason other than warning others of your presence.

Penalty: on summary conviction, imprisonment for up to one month or a fine not exceeding level 3 on the standard scale (£1,000), or both. No automatic licence endorsement (it is not a driving offence per se).

Common myths — these are NOT illegal

Just as useful as knowing what's an offence is knowing what isn't. The following are common misconceptions:

Why this matters for theory test candidates

Most of the offences above appear on the theory test in one form or another — sometimes directly (the horn-at-night rule and the eyesight rule are common questions), sometimes indirectly (questions on "responsibility for ensuring passengers wear seatbelts", which is about being "in charge" of the vehicle). For learners specifically, the 6-point hand-held phone offence and the 6-point no-insurance offence are both single-handedly enough to revoke a licence under the New Drivers Act in the first two years. Knowing the actual law (not the pub-conversation version) is part of the test.

Sources

• GOV.UK — The Highway Code (full text)
• legislation.gov.uk — Road Traffic Act 1988 (sections 3, 5, 42, 96, 143, 165A)
• legislation.gov.uk — Road Vehicles (Construction and Use) Regulations 1986 (regs 30, 99, 100, 110)
• legislation.gov.uk — The Road Vehicles (Construction and Use) (Amendment) (No. 2) Regulations 2022 (SI 2022/81, 25 March 2022 phone-use tightening)
• legislation.gov.uk — Smoke-free private vehicles legislation by nation: England (SI 2015/286), Wales (WSI 2015/1363), Scotland (asp 2016/3), Northern Ireland (SR 2021/328).
• legislation.gov.uk — Police Act 1996, section 89 (obstruction of a constable)
• GOV.UK — Endorsement codes and penalty points