Note to American tourists who may be driving round Scotland: those signs by the side of the road, the ones with the little cameras on them? They are to warn drivers about speed cameras up ahead, not an indication of a nice place to take pictures.

And those stickers on the cars in front, the ones that say "Arnold Clark"? That is the name of a business, not the name of a man who is running for president.

Scotland does not have a president, despite appearances.

I say this for the benefit of all Americans but two in particular: Les and Patty Sontag.

They are a lovely couple from Illinois who have a passion for everything Scottish but during their recent visit here, they did rather get the wrong end of the stick on some of our customs and ways, including those speed camera signs and adverts for car companies.

"Who is Arnold Clark?" asked Patty. "Is he running for office?"

The Sontags did seem to be having a good time though, driving through Scotland and being filmed for a documentary called Life And Death On The A9 (BBC One, 9pm).

The programme also followed a number of other people including the team of policemen who patrol the road and a trucker whose office typically weighs 40 tonnes and moves at 40mph.

The BBC's interest in the road, and the people who use it, is legitimate.

As the narrator said, the A9 has a legendary status in the Scottish psyche largely because it is inspiring but frustrating to drive, a 270-mile spinal cord through beautiful countryside but also, for most of those 270 miles, single carriageway only.

Drivers get fed up and make mistakes. There were 122 accidents last year and seven deaths.

Partly in an attempt to fix this, the stretch of the A9 between Perth and Inverness is be upgraded to two lanes at a cost of £3bn, and we met some of the residents who will have to put up with the extra noise and bother.

Perhaps they can comfort themselves with the fact the journeys on the new road will be so much faster and efficient (if it weren't for the average speed cameras, which are also being installed on the road).

At one of the public meetings about the upgrading, a man in a beard made the good point that new roads only solve the problem of congestion temporarily - after a while they just fill up again, which was proved by the archive footage of the last time the A9 was upgraded in the 1970s.

Before then, driving the road could take nine hours but the upgrading seem to solve the problem.

Thirty years later, the problem is back.

The documentary offered no solutions, no alternatives to the idea that the world must fit round the car.

But perhaps it didn't have to because its most powerful image was one that reminded us that accidents happen on the A9 all the time and will keep on happening.

It was a picture of an upside-down car and a team of paramedics gathered round the driver, doing what they could to save his life.