In December, the European Union banned insurers from setting their prices according to gender.

London - Picture the scene. We are late for Sunday lunch - the clock reads 12.30pm and my wife Charlotte, our three daughters and I are stuck in traffic on the M25, 200km from my parents’ house.

In the back, my two eldest are arguing over a dismembered head (fortunately it is of the toy variety) while the three-year-old keeps reminding us that she needs the loo.

As for my wife Charlotte, the later we get the more insouciant (and infuriating) she becomes. Because this is a woman whose life is built on the adage that those who wait have much less fun than those for whom they are waiting.

I, by contrast, am wearingly punctual. And so I take advantage of any break in the traffic to “get on”. To be clear, we’re not talking Stirling Moss here, just “getting on” when the traffic on the road eases from time to time.

It was a stop-start journey I’d almost forgotten about until earlier this week when Charlotte smugly thrust the laptop under my nose.

The reason for her unconcealed delight was that for the past three weeks we have been competing to establish once and for all who is the better driver. Now she had cast-iron proof that she’d won the challenge, and it was the dash to Sunday lunch at the end of December that tipped the argument in her favour.

Our respective ability in the driving seat has been a bone of contention since we first met 20 years ago. It’s not that my wife is a bad driver. Or that I’m particularly good - just that I’ve always thought I’m better than she is.

On that basis when there are joint journeys to be undertaken, I feel it is my duty to take the wheel. When she does drive, I like to assume the role of a helpful, avuncular instructor.

Charlotte, sadly, has never taken the advice in the generous spirit in which it is offered.

But how do you prove who is the better driver? We both passed our tests first time and have, thankfully, both driven for years without serious incident. And so it was that we jumped at the chance to have our driving skills analysed.

This was achieved by having a high-tech little black box installed in each of our cars.

Wiring it in takes an expert less than an hour per vehicle, and once fitted it sits unseen behind the dashboard. The box has a GPS system which records the details - destination, distance and time taken - of any journey in the car.

There is also a motion sensor that picks up how the car is being driven. Between these two devices speed, aggressive acceleration, aggressive braking and fast cornering can be computed.

The data is transmitted from the box to a central database that is run, in this case, by an insurance company called Autosaint.

While this kind of monitoring system has been used by commercial fleets for a while, it is now been installed by insurance companies to monitor driving habits of private motorists. The main market is young drivers for whom the cost of insuring the smallest of cars often exceeds £2,000 a year.

Fit one of these black boxes - the cost of which is included in your insurance quote - and premiums can fall by 30 percent. The idea is simple: the more safely you drive, the less of a risk you are and the lower your insurance should be.

Figures from the British Insurance Brokers Association show that black-box motor insurance sales have increased five-fold in the last two years, from 35,000 policies in 2010 to 180,000 in the first half of this year. The number is predicted to hit 500,000 in the next 18 months.

A big boost is expected from women drivers. In December, the European Union banned insurers from setting their prices according to gender. It had been the case that women were routinely offered cheaper deals on the basis that, statistically, they were less likely to have an accident. Now they have a means to prove it.

With that background, my head-to-head with Charlotte assumes more than just domestic importance. I cannot afford to lose. Using the Autosaint technology on our respective cars - she drives a Ford S-Max and I drive a VW Passat - Charlotte and I are able to log on to a dedicated website on to which our driving data is uploaded.

The page, set up to look like a vehicle dashboard, is divided into three sections. Read outs are given on how you are doing with regards to acceleration, braking and speed. There is a possible 100 points for each one. From this an overall mark is then calculated.

Individual journeys can also be scrutinised, a map-like display revealing not only the route taken but the time and location when a speed limit was exceeded, or when there was harsh braking or accelerating.

Of course, it would be possible to manipulate the results and drive like a nun. But with a busy life and three kids to ferry around I don’t have the time, inclination or foresight to do that. So from the minute the box is fitted I drive as normal, not bothering to check the results during the trial.

When I do, I’m delighted to discover that I am the winner. My overall score stands at 91. Charlotte notches up a creditable 84. Victory is mine.

Charlotte goes off to study the figures more closely. I, meanwhile, scan the Halfords website for some string-backed driving gloves.

Then she goes and ruins it. She points out that my score since the start of January was 84 - including full marks for acceleration and braking but just 53 out of 100 for my speed (‘improvement needed’ the website tells me).

Her score for the same period was an impressive 97. Therefore the only reason her overall score for the entire period fell below mine was because of the December scores and that included a big fat zero for speed (‘vast improvement needed’).

And what had forced the number down? Primarily it was that journey to my parents - a trip in Charlotte’s car, but with me at the wheel. Discount those scores and I can’t deny there’s only one winner - and it certainly isn’t my heavy right foot.

Tom’s wife Charlotte says:

My driving skills, or lack of, have been a constant source of ribbing throughout our relationship.

I’ve learnt to ignore this, but secretly it does rile me that Tom’s always assumed he’s the better driver, and I’ll admit I am a liability in a multi-storey, particularly around pillars. I would rather drive to an empty level than try to manoeuvre into a tight space between two cars.

But, on the road, I’ve always felt I was a match for Tom, so I couldn’t help but gloat when the results came back. Not only did it highlight the fact that he was driving my car in December when it racked up its lowest score, but also other differences in the way we drive.

Comparing identical journeys - the school run - reveals Tom clocks up more black marks for harsh acceleration and harsh braking. It’s not a surprise. He’s a man and impatience seems to be in his DNA. The reason, no doubt, that insurance companies worked out the obvious - women are safer drivers.

And if I could only master the three-point turn and get out of the drive without scraping the bumper, I think even Tom might be convinced. - Daily Mail