How do you define 'Careless Driving'?

On Monday, new rules come into force for sentencing careless drivers. Drivers who injure or even kill others through lack of attention can now be jailed for up to five years, as opposed to the previous maximum sentence of a fine and disqualification. This actually sounds quite sensible legislation for a change, but as ever, the devil is in the detail. What, precisely, distinguishes 'careless' from mere 'mistake'?

Chatting on your mobile while hurtling along the motorway is dangerous, and presents a very real risk for others around you. Hopefully, we'll all agree with that. But is it as dangerous, or is it even dangerous at all, to receive a call when sat in stationary traffic? (The law says it is - you're not guaranteed to avoid a conviction unless your handbrake is on and your engine turned off. ) But phone have specific legislation already - this new piece is intended for other instances of lack of attention behind the wheel. The Ministry of Justice gives these examples: reading a text message, glancing at a map, eating, drinking, tuning a radio, putting on make up. I'm not into makeup (well, not that I'll confess in this blog anyway) so I'll go along with the flow on that one - it sounds pretty distracting to me. Reading a text message? Well yep, I'll give them that one too. I'm also somewhat renowned for getting lost a fair bit, and it takes all my concentration and more to understand a map, so that ones okay in my book too. But hang on, whats this? Tuning the radio? Eh? Our Galaxy has a button for this on one of the steering wheel spokes, in fact its a further stretch of the thumb to get to the horn than to switch stations! Thats 'careless'? Ummm, I dont think so. Eating too - I genuinely cant imagine a scenario where chewing on a Mars bar can affect my ability to react to things around me. And drinking - can anyone point out why my car has a cupholder, if not to accommodate a can of pop?

You cant legislate for stupidity, and I can think of many examples of drivers who have their full attention on the road but who I think are much more dangerous than a 'decent' driver sucking on a Polo mint. Seemingly, though, NuLiebour want to maintain their record of introducing on average one new law per day in power, and it was just our turn again. The problem (not unusually) lies in what isn't said. Will smoking a cigarette be a valid reason for a prison sentence? Sneezing?