All road users face varying light conditions throughout a 24hr period and throughout the year and a motorcyclist is particularly affected by this variance. There are three distinct periods in which there is a relatively constant amount of light.
There is the period between Dusk & Dawn which is Night & Dark.
There is the period between Sunrise & Sunset which is Day & Light.
There is the period between Sunset & Dusk or Dawn & Sunrise which is Twilight.
All light conditions are generally changing throughout the day according to the angle of the sun and the type of weather (Clouds etc) that obscure the sun & sky. This can dramatically change overall lighting conditions from a day with bright sunshine and blue skies to a dull overcast day.
The period approaching sunset and shortly after sunrise are particularly important as at these times the angle of the sun is particularly low on the horizon, which may shine directly into the rider’s or driver’s line of sight which may cause a temporary artificial blindness. Also during this time, long casting shadows may be formed from buildings or trees etc which may cause a temporary reduction of effective vision, especially when riding from bright sunshine to dark shadow, as the eye is slow to react to the sudden drop into low light conditions.
During the period of Twilight, the rider or driver will notice a rapid change in lighting conditions as the sun either rises up to the horizon or falls beneath the horizon. Whilst looking above the horizon, it may appear that there is sufficient light, the actual ambient light directly ahead of the rider or driver on the road might be considerably less, with it effectively being dark.
The period of Night also has variations of lighting according to the scale and angle of the moon and the type of weather. Also factored in are other light sources of urban areas or street lighting and other vehicles, and the effects of these on the rider or driver are also affected by any obstacle that would likely obscure the light, thus effectively casting a shadow.
The rider is particularly effected by varying lighting conditions as it is light that enables a rider to analyse depth and enables the balance required to control the motorcycle.
During the daylight, the rider is able to control the motorcycle a lot easier as the function of the eye is dramatically improved and is able to differentiate depth and speed with greater accuracy.
During the dark, the rider has to factor in decreased eye functionality with reduced depth perception and assessment of speed. Of course the motorcycle is equipped with a headlight which shines light ahead and depending on the type of motorcycle and the year of manufacture, will determine how much light is produced. Modern motorcycles have much improved lighting systems which enable much improved vision, however all motorcycles effectively have large changes in the way light is shone each time the motorcycle is ridden on a bend.
A car, when driven around a bend, is essentially turning in a flat plane therefore the lighting is relatively constant across the road ahead. However, when a motorcycle is ridden around a bend, the rider has to lean over the motorcycle which changes the lighting angle of the headlight, thus there is less light in the inside of the bend and more on the outside of the bend. A similar situation occurs under braking, as the light angle is forced down, hence there is more light down and directly ahead and less above and far ahead.
Motorcycle accidents occur at all time of day & night, with more during the day due to there being more vehicles on the road.
A common time of day for all types of road accidents is during Twilight and just after sunrise and just before sunset as the angle of the sun or rapid changing light can cause a rider or driver to either lose control of the vehicle or not ‘see’ a hazard that is developing ahead of them due to the ‘artificial blindness’
Accidents at night do occur in lesser numbers due to less vehicles on the road, however they are largely still attributed to excessive speed and reduced control due to diminished perception because of the low light conditions. I am not considering accidents that are caused either as a result of alcohol, narcotic or prescribed drugs or by medical conditions in this article as those would be considered as an external causation factor in this sense.
The key to riding at night is:
First, the acknowledgment that there is less light and hence there is less ability to see the road and hazards as clearly.
Second, allow extra time for the journey and extra space between vehicles and this is achieved with reduced speed at night.
Be sure that your motorcycle is suitable for riding at night, either because of it age or design, does the headlight provide sufficient light to provide adequate lighting for the road ahead. Of course be sure that all lights are working properly.
See & Be Seen! Pay extra attention during the dark for hazards and other road users that may not have seen you. Remember that all road users will have a diminished performance in the dark and coupled with fatigue there is a possibility that the other road user may not notice you as a rider or may misjudge your speed.
All riders may consider wearing high visibility or reflective clothing especially at night, however very importantly every rider should not over rely on the other road user still seeing you even if you are wearing HV clothing. All riders should remember that an oncoming vehicle will predominantly only see the motorcycle headlight from distance and whilst drawing nearer. Only in the passing phase may the driver notice the rider wearing HV, hence the HV has not contributed to any avoidance. HV may assist a rider when a vehicle is approaching a motorcycle from the rear. Motorcycle tail lights can be quite small and the light derived from them, especially when riding in urban areas with substantial street lighting can be perceptually less. In this circumstance the wearing of HV may assist the driver to see a rider, but this is not guaranteed.
For any novice night rider, the best advice is to practice in night riding techniques. Possibly take some instruction from a training school or slowly build up experience in urban areas where there is more ambient light and then further develop your skills on roads that have been tried in day light conditions and progress from there. As stated the key is to acknowledge the limitations and adopt a riding style according for the light and the weather conditions, which, because of the colder temperatures there is likely to be a deterioration in weather.