Drink-driving is obviously bad, dangerous and stupid, and any technology that can prevent it - and its oft-ruinous consequences - is a Good Thing. Volvo will unveil its no-nonsense solution to the old booze-and-bruise problem at Frankfurt next week with the new Alcoguard.

It's an in-car immobiliser similar to those that have been knocking around for a while: blow into a unit which analyses your alcohol level and only allows the car to start if you're below the legal drink drive limit. If you're close to that limit, the car will start but the unit will give you a warning that you probably shouldn't take to the road.

The difference between the Alcoguard and older systems is that it uses fuel-cell technology for a more accurate blood alcohol reading. It's the same technology that many police forces use in their breathalysers and, according to Volvo's technical director, is much more reliable at picking up ethanol levels rather than any false readings.

The Alcoguard will be available as a cost option on the Volvo S80, V70 and XC70 from early next year, and although there's no official word on price, it's expected to cost £500 or so.

But will it make any difference? Although the Alcoguard will be great for the people who want to be saved from themselves, the majority of likely drink-drivers aren't going to splash out £500 for the inconvenience of being stuck at the pub, however much more sensible that option is. The technology sounds good, but the prohibitive cost could drink-drive away those it could help most.

That said, it might prove more popular and useful in rental or fleet cars. We'll have a good sober look at the Alcoguard in Frankfurt to find out more.