Formula One drivers, eh? Nothing but a bunch of overpaid, underworked prima donnas, aren't they?

Well, they may have been once. But modern technology has contributed to a few changes. Imagine spending your working day linked up to a hundred different sensors, so that every move you make can be analysed by your boss. And everyone else in the company, for that matter. Not to mention a few hundred million watching on television in every corner of the globe...

We, though, only tend to see the really big incidents. But ever since Formula One telemetry became so sophisticated, the drivers can't blink without it being picked up on a graphic somewhere back in the factory. In some ways, this feedback is handy - after all, now drivers can check up if they're losing time to their team-mate on any given corner and see how to make up for it. But there is a hefty down side.

Hundreds of people have jobs to do on a race weekend to get a race car into perfect condition. But when the red lights go out on Sunday afternoon, it always used to be in the hands of the driver just to drive the thing. Not any more, because strategy dictates that drivers are constantly told how quick they have to go on any given lap given their fuel load. Now that everyone can see a print-out of drivers' every corner, woe betide if they ever fall off the pace.

Pit-to-car radio provides a perfect opportunity for the technical team to take it out on their high-profile fellow team members, as BAR technical director Geoff Willis explains. "The important thing is that the drivers drive to their lap targets," says Willis. "Every race strategy relies on them being quick enough, so every lap they have to get it right. So we usually bully them, saying, 'you're three seconds behind your target, and you've got to make up three seconds in the next seven laps.' You say after each lap, 'yes that was a good lap, you've got to do that again,' or 'no, that's not good enough, you're doing a 1m 24.2s, you need a 1m 23.5s'.

"We tell them if they're up as well. Jacques Villeneuve's race engineer, Jock Clear, in particular is always talking to Jacques, saying things like 'good lap - you need another three of those, then we'll get the pitstop right and you will beat the person in front of you out of the pitlane.'

"But we will happily bully them too. Drivers vary in how consistent they are, but the best are very consistent. At the end of the race you can look at the full detail lap times, and with the very top drivers, you can see the fuel load and tyre wear just coming down, and they're 0.1s or 0.05s faster every lap. Obviously there's a little variation when they hit traffic, things like that. But it just comes down like a metronome. The Michael Schumachers of this world are like that."

Such is the importance of maintaining pace over a race distance that it has become a crucial factor in driver selection. Indeed, Clear reckons that the differences in outright pace between drivers at the top of the sport are so small now that consistency is the main factor in determining how good a driver actually is.

"There is a limit to how fast any car will go," says Clear. "There is a limit to how much grip any car has, and it's all about finding that limit. At Ferrari in recent years Rubens Barrichello and Schumacher have often been as quick as each other. That's because they've had a car that's well balanced and it's easy to find the limit.

"So Barrichello isn't any slower than Schumacher over one lap - there's nothing in it. But it's all very well qualifying in the same time as another driver. You have to keep it going for 60 odd laps in a race."

Of course, you can only tell a driver to push harder so often during a race. There is a famous story of a British world champion engaged in a crucial late season battle who was repeatedly told to push over the radio. There was no noticeable improvement and radio silence for a couple of laps until the umpteenth request when there was a sudden scream of, 'What do you think I'm doing?'

That makes for a bit of a conversation-stopper. But there are other strands of dialogue going over the airwaves during races.

"We do have a fair amount of conversation with drivers," says Willis. "What we do try to give them, particularly, is what the other driver's doing. In certain conditions they know what their relative fuel loads are. So if Jacques is having a problem, and he wants to know what the track's like, we say: 'Jenson's doing 1m 23.4'. He knows he's just done a 1m 24.1, so he knows he 'best get a bit of a move on'. Or we tell them, 'that's fine - if you keep doing this for the next four laps do you hit your targets.'"

Those targets, of course, can be different for the two drivers - varying over the course of the average race in accordance with the vagaries of traffic and other unforeseen events. Schumacher, for example, is famous for putting in a storming string of 'qualifying laps' around the time of the pitstops to eke out an advantage over anyone who would otherwise try and nip ahead with a shorter stop. In fact, that kind of burst of pace goes on up and down the grid, and it's up to the guys in the pits to communicate to drivers just how much more time they have to find.

Willis explains: "You do the target calculations based on who you're actually racing. For example, you may have been held up behind someone on a different strategy and they come into the pits. If you know that you still have six laps before you have to stop, you use those laps to get in front of them.

"You have to make up for the fact that you're going to have a longer fuel stop - so if you know your stop's going to be 1.5 seconds slower, and you were half a second behind them, then you know you've got to make up two seconds in six laps. When the other guy comes out, you know he's maybe quicker on new tyres, so you say, 'you've got to make up 2.5s in these six laps, otherwise by the time you've come round, he'll be in front of you.' You all know what you've got to do."

All the time, of course, the two BAR drivers are trying not only to outdo the rest of the grid, but also each other. But all information they gain - from their set-ups to their data readings - is shared. That process goes on throughout the race weekend, starting in the briefings long before they get to the race itself. The two cars go into the weekend with different set-ups, but the team publishes set-up comparisons. And, crucially, the two BAR race engineers know what both cars are doing at all times.

It is a situation that continues during the high-pressure time of the race itself - no information that can help the other driver is kept back.

"We've got two separate radio channels, but the ability for the senior guys to talk to each other," says Willis. "The two senior race engineers - Jock Clear and Craig Wilson - talk to each other all the time, acting as the link between the two sides of the team. And I can talk to any of them. I don't talk much, but if I think that one side doesn't know what the other one's doing, then I will let them know.

"So drivers will know when they've got problems. And we'll always make sure that when one side is thinking of when they're going to stop, they'll talk to the other side. If both want to stop at lap 36, then the leading driver has the first choice. There's sometimes a bit of horsetrading. Say, if one side needs to agree go one shorter, and then they may say, 'well actually we don't mind, one way or the other."

Even in the most acrimonious of relationships between team-mates, both sides always know that cooperation is the quickest way forwards. For example, while the media was over-hyping the supposed antipathy between Villeneuve and Button in Melbourne last March, the Englishman surprised all by warning his team-mate that there was oversteer on the last corner in qualifying.

Willis explains: "What is important is that we're saying to Jenson, tell us what the car did. He's not giving Jacques a tip, he's just saying his tyres had started to give up on the last two corners. So in that case Jock would listen to that and say to Jacques you need to have a more gentle out lap, to save the tyres."

If Sunday's sound like one long round of ear-bending for the drivers, then Saturdays must come as something of a relief in comparison - in that there's only one lap's worth of radio time. Thankfully, the calculations also get rather simpler when it comes to one-lap qualifying. But it's even more crucial for the drivers to get it right.

Willis adds: "It doesn't matter what fuel we put in the car, the drivers still have to drive to achieve their target time. So if an empty time is a 1m 21s, and a 50kg time is, say, a 1m 23.2s, if you do a 1m 23.3s you'll be one place down compared to where you should be. And if you do a 1m 22.9s, you'll be one place higher.

"So it doesn't matter what fuel you have on, we can calculate their theoretical position, and they must achieve that. It's equally bad to mess up a lap with no fuel, as it is to mess up a lap with heavy fuel. Unless, of course, you mess it up so badly you spin it, and lose a second and a half, in which case you'd better have a lot of fuel on board, because you're going to be at the back of the grid anyway."

The only other respite the drivers get is that, shock horror, the radio isn't as private a form of communication as it might be...

"People do listen to other radio channels, so we prefer to speak face to face," admits Willis. "Although you can scramble your radio channels, it's a complicated and expensive business and there are only a couple of teams left that still do it. It is therefore technically possible for anyone to tune into other teams' channels. You can even get the local taxi firm sometimes..."