Reduce driving at night

A disproportionate number of road crashes occur at night despite the fact that the number of miles being driven decreases substantially compared with day-time.

Road casualty statistics show that 40% of crashes occur during the hours of darkness and account for 20% of serious accidents on motorways and monotonous roads in Britain (1); injury severity, too, is almost  3 x higher on roads with no lighting (2).

This is because the hours of darkness are when the human body is preparing to sleep, especially after a hard day at work and tiredness can set in quickly. As a result, the danger of falling asleep at the wheel is a significant factor at night with fatigue associated with many night-time crashes (see driver fatigue ).


  • Road crash severity is doubled at night, when averaged across different road types (2)
  • Due to higher average speeds, severity rates are higher on ‘non built-up’ roads with a speed limit up to 70 mph and motorways than on ‘built up’ roads (speed limit up to 40 mph) (2)
  • Sleep-related accidents are most likely to occur between 2am and 6am (4)
  • For older or short sighted drivers night vision is worse e.g. a 50-year-old will need twice as much light to see as a 30-year-old (5)

The issue

Crash data analysis reveals that there are typically 3 major reasons as to why there are disproportionately more road crashes at night than during daylight hours:

  • Braking distance : drivers should adjust their speed to enable them to brake or manoeuvre to avoid a hazard without endangering those around them, and stop within the distance they can see to be clear
  • ‘Perception’ distance - at night the distance a driver can see is shortened and so hazards can often seem to appear out of nowhere. It also takes time for a driver’s eyes to adjust to the darkness after being in a lit building or after driving on a well-lit road.
  • The ‘additional’ distance covered because of the slower reaction time;  in darkness it is harder to judge speed and distance and objects can be closer than they appear or travelling faster than first expected (1 and 2). Therefore, stopping distance should be within the area illuminated by a vehicle’s headlights - if the vehicle’s speed is such that it will come to a stop beyond this then the driver is, in essence, ‘driving blind’ (5).

Statistics show that reduced lighting, as well as other factors such as fatigue, alcohol, or traffic density, contribute to the impaired ability of drivers to avoid collisions at night (2).

Additionally, visual reaction times are substantially longer under adverse, low visibility conditions making it particularly difficult to see vulnerable road users such as pedestrians, cyclists, and motorcyclists than under optimal conditions, leading to increased stopping distances when driving.

Consequently, the Highway Code advises drivers to “reduce speed when driving at night as it is more difficult to see other road users” (3).

However, introducing road lighting leads to an approximate 3 x decrease in the severity of injuries in the UK.

Nevertheless, whether driving on lit or unlit roads at night, The Health and Safety Executive’s ‘Driving at Work: Managing work-related road safety’ guidance (4) makes clear that employers have a duty to ensure that drivers know how to carry out routine safety checks such as those on lights as well as being made aware of the dangers of fatigue and what to do it they start to feel sleepy

If employees do have to drive at night then they should plan the journey ensuring that they are well rested before the trip and book overnight stops where necessary, rather than having to complete a log road journey at the end of the working day (1 and 4). Additionally, they should avoid driving at times when they would usually be asleep.

It is illegal to drive at night without fully functioning front and rear lights therefore all vehicle lights should be checked that they are in full working order and kept clean before the start of a journey.

How ProFleet2 can help

There is much that can be done to reduce the risk of drivers being involved in an accident , the most obvious way being to avoid the dangers by  simply not driving at night ! However, such a goal can only be achieved if fleet decision-makers know when employees are driving which is where ProFleet2 can help.

Having identified individual employees that are travelling during ‘high risk driving hours’, work schedules can be revised to ensure that, as frequently as possible, journeys are made during daylight hours.

Additionally, information can be distributed to employees to make them aware of the increased risks of driving at night alongside advice on how, if they must drive during the hours of darkness, they can reduce the likelihood of being involved in a crash.

As a result, data gathered via ProFleet2 may save the life of at least one of your drivers and reduce the risk of road traffic and health and safety offences being committed by drivers and the company.

Driving at night tips

  • Use  lights courteously;- pointing downwards slightly, otherwise they will dazzle other road users and not light up the road ahead sufficiently (5)
  • Make it easy for others to see you;only turn on full beam if alone on the road, and use dipped headlights if  not.
  • Avoid glare; if a driver is the ‘victim’ of someone else’s full-beam, slow down and, if necessary and it’s safe to do so, stop the car until the eyes recover (5)
  • Adjust your vehicle’s interior lighting
  • Keep all windows and headlights clean
  • Keep your eyes moving
  • Increase your following distance - if driving too close to the car in front, the headlight beam will bounce off the rear of the vehicle, reducing visibility and interfere with the other driver’s vision when they check their rear-view mirror (5)
  • Regulate speed
  • Prevent fatigue
  • Use vehicle mirrors

Information sources

  1. RoSPA,
  2. ‘Road Traffic Casualties: Understanding the Nigh -Time Death Toll’ by S Plainis, I J Murray, and I G Pallikaris published by BMJ Publishing Group
  3. Highway Code,
  4. ‘Driving at Work: Managing work-related road safety’,
  5. Privilege Insurance,