Road Safety

[Kofi]

What is road hazard

[rampart]

A hazard is a danger or risk. A road hazard refers to something in the road.

Examples:

A box falls out of a vehicle and is in the middle of the road.

A tyre explodes and leaves debris on the road.

It rains and the road has oil on it and becomes slick.

A cow gets loose and wanders into the road.

[hedgehog661]

A hazard in road safety is anything that moves across your path or has potential to move across your path causing you to alter speed or direction.

[Jay70]

Bassically anything that can endanger the safety of any road user.  Some good examples have been given previously but It can refer to someone using the road too.  It also doesn't have to be anything that moves as hedgehog has posted it can also be a staionary object. e.g.

A stationary car on a blind bend.

A tree across the road.

Someone changing a tyre in the outside lane of the M1 (Which I've seen) 

[lethologica]

If this question is regarding the hazard perception part of the theory test, then a hazard is anything which may cause you to change direction (e.g. swerve) or slow down.

[Tim Baxter]

A hazard is anything which may cause you to change speed or direction in your car.  N.B. Change speed means faster or slower.