The short version
- Lights required in poor daytime visibility
- Whenever the 150-metre test fails, any time of dayRegulation 157(1)(b)
- Fog lamps
- Only in poor visibility caused by snow, fog, mist, dust or smokeRegulation 163(6)
- Following distance in rain or fog
- Longer than in good conditions — no fixed figureRegulation 308(1)(b)
- Hazard lights while driving through fog or rain
- Not what the switch is forRegulation 198(6) — only a stationary hazard or a moving emergency
The rule that covers both night and bad weather
Regulation 157(1)(b) is written to cover two different causes with one test. Head lamps, rear lamps and number-plate lamps must be lit between sunset and sunrise, and — separately — "at any other time when, due to insufficient light or unfavourable weather conditions, persons and vehicles upon the public road are not clearly discernible at a distance of 150 metres".
Heavy rain, thick mist or blowing dust at midday can fail that 150-metre test as completely as darkness can, and the regulation makes no distinction between the two causes. If you can't see, or be seen, at 150 metres, your lights go on — the clock has nothing to do with it.
Fog lamps are not everyday running lights
Regulation 163(6) states plainly that no person shall operate a vehicle on a public road with any fog lamp lit, except in conditions of poor visibility caused by snow, fog, mist, dust or smoke. Running them all the time — dawn, a sunny afternoon, city traffic — is itself a contravention, not a harmless extra.
The regulation is built around that restriction elsewhere too: a front fog lamp is only permitted to emit a dipped-beam pattern, and a rear fog lamp can only switch on together with a front fog lamp or a head lamp, so the system is designed to come on as a pair specifically for degraded conditions, not as a standalone accessory.
Slow down and open the gap, and know what the standard is
Regulation 308(1)(b) requires a following distance that is reasonable and prudent, having regard to the speed of the vehicle ahead, the traffic, and the condition of the roadway. No figure is prescribed anywhere in the regulations — but "the condition of the roadway" is exactly what changes in the rain or the fog, so the same rule requires more space than it would in the dry.
Section 63 of the National Road Traffic Act backs this up from the other direction: in deciding whether a driver has driven recklessly or negligently, a court has regard to the nature and condition of the road being used and the traffic on it at the time — the standard a driver is judged against moves with the conditions, not just the rule on following distance.
The mistake
Switching on the hazard lights instead of the head lamps when visibility drops. Hazard lights aren't a general poor-visibility signal — regulation 198(6) limits the all-indicator switch to a vehicle stationary in a hazardous position or moving in an emergency, and using it while driving normally through rain or fog is outside both.
The other one is leaving fog lamps on once the weather has cleared. Regulation 163(6) makes their use conditional on the actual conditions, not a setting you switch on for a drive and forget about.
This sits inside the rules of the road section
Visibility and lighting questions are scored with the rest of rules of the road, separately from signs and vehicle controls. The free readiness test takes a couple of minutes and shows you the three sections apart.
Take the free readiness testCommon questions
Do I need my headlights on in daytime rain or fog?
Yes, if it means people and vehicles on the road aren't clearly visible from 150 metres. Regulation 157(1)(b) treats that the same as darkness — it doesn't matter what time of day it is.
When am I allowed to use fog lamps?
Only in conditions of poor visibility caused by snow, fog, mist, dust or smoke, under regulation 163(6). Using them in clear conditions is itself a contravention, not just unnecessary.
Should I use my hazard lights when driving through fog?
No. Regulation 198(6) restricts the all-indicator switch to a vehicle stationary in a hazardous position or moving in an emergency, and prohibits it in every other circumstance — driving normally through fog isn't either of those.
Should I follow more closely in the rain to see the car ahead better?
No, the opposite. Regulation 308(1)(b)'s reasonable-and-prudent standard is judged against the roadway's condition, so a wet or foggy road calls for more distance than a dry one, not less.
Sources
- National Road Traffic Regulations, 2000 — regulation 157(1)(b)Head lamps, rear lamps and number-plate lamps shall be kept lighted between sunset and sunrise, "and at any other time when, due to insufficient light or unfavourable weather conditions, persons and vehicles upon the public road are not clearly discernible at a distance of 150 metres".
- National Road Traffic Regulations, 2000 — regulation 163"Fog lamps". Subregulation (6): no person shall operate on a public road a motor vehicle while any fog lamp fitted to it is lit, "except in conditions of poor visibility caused by snow, fog, mist, dust or smoke".
- National Road Traffic Regulations, 2000 — regulation 308(1)(b)A driver shall not follow another vehicle more closely than is reasonable and prudent, having regard to the speed of the other vehicle, the traffic, and the condition of the roadway.
- National Road Traffic Regulations, 2000 — regulation 198(6)The all-indicator hazard switch is required only when the vehicle is stationary in a hazardous position or moving in an emergency, and its use in any other circumstance is prohibited.
- National Road Traffic Act 93 of 1996 — section 63"Reckless or negligent driving". In deciding whether section 63(1) has been contravened, a court has regard to "the nature, condition and use of the public road", the traffic on it, and the speed and manner of driving.
Last updated 2026-09-23.