Sir Liam Donaldson is a nutter, Part 2

Sir Liam Donaldson is the government's chief medical adviser. Recently, he's been arguing in favour of a new policy: a minimum price per unit of alcohol. That might get rid of the odd handful of dangerously cheap all-you-can-drink deals and promotions, but it'll also force sensible and moderate social drinkers up and down the country to pay more money.

You can argue the toss as to whether this is a good policy or not. Personally, I don't. But the main thing that bothers me is this: why does Donaldson see it as his business to come up with public policy? He's there to advise the government about medical science, so that they can come up with policy measures.

This isn't the first time that Donaldson has put forward ideas that are out of touch with reality. As I blogged last summer, his plans to cut the drink/drive limit for younger drivers were well-intentioned, but dangerous. But when a medical adviser unilaterally decides to invent sweeping measures that touch on licensing law, taxation and highways enforcement, it's not surprising that he comes up with junk.

Now, I'm not for a moment doubting Sir Liam's scientific expertise, and I'm not for a moment claiming that I could come up with any better suggestions of my own. But I would like to think that the state response to alcohol problems is formulated by the Department of Health on the basis of a lot of research and consultation, taking on expertise from a range of different sources. Just introducing something that the CMO dreamed up one evening at the pub is unlikely to make for good law - and if he does want to make the law, why doesn't he just stand for parliament?

Drink-driving: how to send completely the wrong message

The government's Chief Medical Officer, Sir Liam Donaldson, has urged ministers to cut the drink-drive limit to zero - but only for young drivers. For anyone older than 20, the current limit of 80mg per 100ml of blood will still apply.

At first glance, it seems like a good idea. Fewer young people will drink and drive, and we'll all be much safer.

But there's a very serious flaw in the plan. Even with the current 80mg limit, it's impossible to judge how much you can safely drink and still get behind the wheel. Every single piece of official advice says the same thing. I quote this from the Department for Transport's own website: "... the only safe option is not to drink alcohol if you plan to drive ... You can't calculate your alcohol limit, so don't try."

Unfortunately, if you have two separate limits in force, what you're doing is sending the message that it's somehow possible to tell between them. So whilst the under-21s might start to avoid alcohol completely when driving, older drivers will get the impression that it's alright for them to drink a little bit, so long as they stay within an 80mg limit which they can't possibly judge with any accuracy. Sir Liam may have his heart in the right place, but his comments seriously undermine the government's own campaign against drink-driving.

Just imagine the slogan - "Think! Don't drink more than a pint (give or take, depending on your height, weight, sex, ethnicity and personal alcohol tolerance) and drive."

Surely the right strategy would be to set a nominal but very low limit, perhaps half of the current one? It would be impossible to have an alcoholic drink worthy of the name and still be allowed to drive, but it would also protect people from getting arrested for having a trace level in their blood from a drink they'd had hours before. You could then send out a strong and consistent message to drivers of all ages: don't get behind the wheel unless you're completely sober.

This sort of thing happened during the debate on the smoking ban, and we're seeing it again. Government medical advisers may well be good at explaining the science to ministers, but they're extremely bad at coming up with actual policy!

Road pricing - it's about trust, not transport

I've just had an email from the Prime Minister. This is because - and I don't mind admitting this - I'm one of the 1,800,597 people who have signed the petition against road pricing. This has been making waves in the media for the past few months, but on the off-chance that any of my fellow Lib Dems agree with me, it's too late to add your name. The petition's now closed.

Considerably more of my yellow-feathered colleagues will be wondering if I've flipped my lid, and joined the gas-guzzling motorist lobby. The other signatories, they'll argue, are simply after a licence to damage the environment for free, and no liberal has any business suporting them. But I assure you, I haven't got into bed with Jeremy Clarkson (although he does make very entertaining TV).

The stupid thing is, even though I've signed this petition, I think that road pricing is quite a good idea. Replacing flat-rate road tax with a scheme that takes distance into account is extremely clever. It's much fairer, it gives people a real incentive not to use their cars for pointlessly short journeys, and it penalises people for being irresponsible motorists, rather than just being motorists in general. More to the point, the maths suggests that it would do a very good job of cutting congestion.

So why am I joining the majority of sportscar drivers in this country in petitioning the PM? Simply because I don't trust him. I want him to scrap the road-pricing scheme, not because road pricing is bad, but because this particular scheme will be implemented by New Labour, and I cannot trust New Labour to do what they've promised.

By an accident of birth, I escaped the top-up fees that Labour promised not to introduce. By renewing my passport this year, I've bought myself a decade's freedom from the ID cards that Labour said would be completely voluntary. And when I go to the polls at the next general election, I'll be voting under the same rigged voting system that Mr Blair promised to replace in 1997.

So when he tells me that road pricing will simply be used to send everyone a bill at the end of each month, I get alarm bells in my head. The next time there's a black hole in Brown's budget, will I start getting speeding tickets in the post? Or more worryingly, if I'm ever suspected of a crime with political implications, will the press start to get anonymous briefings about where the Government thinks I might have driven? Access to tracking data from every car in the country is a huge amount of power, and it's not the sort of power I want our country's top brass to get their hands on.

This debacle isn't a matter of transport policy; it's a matter of trust. And on the last day of the road pricing petition, I have no regrets about my name being up there on the Number 10 website, however many 4x4 owners' are alongside it. Say yes to distance-related road tax, yes to real incentives for people to drive less - but for pity's sake, say no to a virtual Government monkey on my shoulder whenever I drive.