Alcoguard works by measuring the amount of alcohol in the driver's breath; if there's too much, the car will refuse to start. As standard, Alcoguard is set to the Swedish limit of 20mg of alcohol per 100ml of blood, but it can be adjusted to the UK limit of 80mg/100ml by Volvo dealers.
Volvo emphasises that Alcoguard should be seen as "a supporting system". There are ways round it; for example, there is a bypass function that can be activated in emergency situations, or if the wireless handheld unit is lost. Let's hope the bypass is too complex for a drunk person to be able to remember it.
Alcoguard will be offered as an option on V70, XC70 and S80 models early next year, and on other ranges later in the year. Sales projections are modest, at 2000 annually, though Volvo expects that this figure will increase as time goes on.