Why is it often safer to lower your speed limit to below the posted speed ?
Busy roads are full of unexpected problems. A child may see its parents on the opposite side of the road and dart across without looking. You may be in control of your vehicle but you can’t control what other road users may do.
If you reduce your speed, you have more time to react to an unexpected situation.
When roads are wet and slippery it takes much longer for your vehicle to come to a stop after applying the brakes. When it rains after a long period of dry weather it is even more important to go slower, as the rain mixes with oil and dust on the road, making it even more slippery than usual.
Bright sunlight can blind you just for a moment when a hazard appears in the distance. If you are travelling at a slower speed you have time to react safely.
If you are travelling in an unfamiliar area, you will not be aware of the dangers that are around. By slowing down, even by 5 km/h, you give yourself an opportunity to see any hazards and more time to react.
Remember, the slower you go, the more time you have to react to unexpected situations.
Source: ATSB Key Facts For New Drivers