Crash! One evening last week I was standing at a bus stop to see off a friend and her three boys, when, only a few yards away, a guy cycled across the road and straight into the kerb on the other side.

Over the handlebars he went, landing on his helmet-free head. Ouch!

We ran the fifty yards as fast as we could while the guy tried desperately to get up, not succeeding.

Even under the streetlamps it was still possible to see a large bump on the side of his head, and a stream of blood slithering down his ear.

My friend made sure he was safe before phoning an ambulance, while I confess that I quickly checked his bike to see if it was okay.

There was some confusion on the phone over the location, because if you call from a mobile you go straight to a national emergency services call centre rather a local one (this might be a reason to head for a call box rather than use your mobile if you ever find yourself in an emergency).

Meanwhile, our cyclist friend was adamant he was fine and just wanted to be on his way.

My friend and I sweet-talked him into staying put, and after just two minutes a friendly cycling bobby pulled up, followed shortly afterwards by an equally friendly ambulanceman. We left the guy in their capable hands and returned to the business of getting my friend on to her bus.

Looking up accident statistics afterwards, I found that such incidents are, unfortunately, not uncommon.

According to the figures, in 2007 in England alone, some 9,191 cyclists were injured in incidents involving no other vehicles, while 518 hit stationary objects. A further 208 collided with other cyclists, and 89 crashed into people or animals.

While there would undoubtedly have been a whole variety of reasons behind these accidents, I’m sure alcohol would have been a contributing factor in many.

There have been many tests to look at reaction times of drivers after taking alcohol or drugs, and more recently similar tests on cyclists. All of them show that despite the cyclist or driver feeling more confident, they actually notice fewer other vehicles, road signs or pedestrians, and reaction times are slower. With cars we know this means they are likely to hit other road users; with cyclists, it’s most likely ourselves we hurt.

Now, I’m not here to judge. I’m sure many of us have cycled back after a night at the pub and have been convinced that, even with several pints inside us, a ride home will be easy. But as I witnessed the other night, it only takes a momentary lack of judgement to have potentially dire consequences.

And it’s not only drink or drugs, but emotions such as anger, grief and stress that can also impede your ability to concentrate on the road.

So, for what it’s worth, my advice is before you make your journey, take a few seconds to think about the state you are in and whether you are in a fit state to cycle safely.

And if you need any further incentive, think about the consequences to your bike of crashing into a kerb or colliding with a lamp post.

In the end, a few seconds’ thought can save a shedload of future trouble.