Having a clear vision forward is without a doubt the most important element of safe driving. Poor visibility can increase the risk of a crash by 30% or greater so it is important that drivers know exactly how to adjust their behaviour when they experience poor visibility. Without adequate visibility, we are unable to judge when to slow down, speed up or avoid obstacles on the road.
What is poor visibility?
Poor visibility is when road users cannot clearly see a distance of 100m ahead due to unfavourable conditions, such as low light, sun glare, rain, fog or dust. This often occurs on country roads, during a storm, on a glary day or at night-time.
These types of scenarios are challenging because our eyes have difficulty adjusting which can affect our depth perception, peripheral vision, and ability to distinguish colours.
Driving at night time
Driving during the night can significantly increase your chances of having an accident. According to the National Highway Traffic Safety Administration in the US, fatal accidents are three times more likely to happen at night compared to daytime.
Why is driving at night time more dangerous? At night-time, your line of sight is restricted to the range of your headlights. This means that unexpected hazards can often seem to appear out of nowhere. It can also be harder to judge speed and distance at night-time which is why it is important to be on the lookout for vulnerable road users such as pedestrians, cyclists, and motorcyclists and wildlife.
Driving in direct sunlight
Have you ever experienced a moment of blindness when driving into the sun when it is low in the sky? This is a concept referred to as sun strike.
Sun strike is particularly dangerous because the sun sits low in the sky during morning and afternoon peak hour traffic. If you do experience momentary blindness during heavy traffic, you are more likely to be involved in an accident with a nearby vehicle.
It is therefore important to take precautions during your peak hour travel such as setting your sun visor and keeping a pair of polarised sunglasses handy in your glove box.
Driving in a storm
Driving in heavy rain has been shown to increase the risk of a crash by up to 71% compared to driving in dry conditions. Wet roads reduce braking distances and restrict the range of vision, similar to driving during the night. This makes it difficult to make clear judgements about speed and distance.
It is therefore important to reduce your speed, allow a larger distance to the car in front (crash avoidance space) and be prepared to stop if necessary.
Safe driving tips
If you drive regularly for work, you are likely unable to avoid some of these common unfavourable conditions. So what should you do if you can’t see the road ahead of you?
Regularly maintain your vehicle
You need to ensure that your vehicle is prepared for unfavourable conditions before you start the engine. This includes cleaning the windscreen, aligning your headlights and check your indicator and brake lights. It is important that your demisters are working in case you encounter fog and that your windscreen wipers are in good condition.
Use your lights
Make sure that you are aware of your different light settings and how to use them. You can use driving lights for low light or medium visibility conditions. Headlights can be turned on once the sun is down as they illuminate more of the road forward. High beam lights should only be used in challenging driving conditions such as country night driving where you require greater illumination. You need to ensure that there are no oncoming vehicles as high beams can cause vision problems for other drivers.
Keep your distance
Low visibility conditions can lead to unexpected hazards appearing out of nowhere, meaning you have less time to brake. Even with your headlights on, your brake time is minimised and your reaction time needs to be quick. In low visibility conditions, you may need to reduce your speed below the speed limit to ensure that you are keeping an appropriate distance between the car ahead.
Be mindful of others
Driving in poor visibility conditions is stressful for all drivers on the road so be mindful that other vehicles may be slowing down or pulling over as a result. You must be taking extra care in looking out for vulnerable users on the road including motorcyclists, bicyclists and pedestrians. It is more difficult to spot cyclists and pedestrians with poor visibility and the consequences of colliding will be much more severe than if you are involved in an accident with another vehicle.
Pullover where you can
If your visibility of the roadway is so poor that you can’t see past the bonnet, then it is unsafe to continue driving. By continuing to drive in these conditions, you are significantly increasing your risk of a fatal accident, especially if other drivers are continuing to drive in these conditions. If you feel at risk, immediately pull over and turn your hazard lights on. Once visibly of the roadway returns, you can continue on your journey.