Grosjean asks for speed delta system in blue flag debate

Romain Grosjean wants F1 to become open to the idea of introducing a speed delta system which would control overtaking in blue flag situations after the latest clashes between drivers.

The French driver's Haas team-mate Esteban Gutierrez came under fire in both Hungary and Germany for holding lead cars up while seeing blue flags waved to let cars lap him.

Grosjean, who had a similar incident with Sebastian Vettel at Hockenheim, admits it is difficult to police given each incident is likely to have different circumstances and feels when lead cars are marginally faster than the back-markers trying to force an overtake can hamper both drivers' races.

"When [the leaders] are coming on new tyres or the same tyres and they're faster it's easy," Grosjean said. "I had Vettel behind me and he was about two tenths faster because he was on old tyres and I was on super-softs so of course it would take him 10 laps to close a two-second gap. I did a few laps in front and then we had a warning from Charlie [Whiting] and I let him by but it cost us 2.6s in one straight line so that was a lot of time lost.

"You are not happy because you're fighting to go to the points as well. But they are the leaders... I don't know. There is no right or wrong answer."

OPINION: Why the FIA shouldn't be forced to right its wrongs

Grosjean has suggested to Whiting and his rivals about implementing a speed delta system which measures the time the lead car is catching a back-marker in order to provide a consistent alert programme when drivers should move over to be lapped.

Currently, when lead cars are within two seconds of a back-marker blue flags are automatically triggered regardless of the pace of each car.

Grosjean says the drivers have a split opinion on the subject but feels the current system is difficult for race direction to manage as each incident can produce different results regarding time lost or gained for each driver.

"Ideally, I think I would like a blue-flag system which is in function on the speed delta in between the cars," he said. "If they are one second faster per lap, then the two-second mark is fine. But if they are only two tenths faster per lap... you see them in the mirrors and they are miles away and not catching up. So you're like 'Why should I let them by?' But that would be a tough software [to implement].

"We discussed about doing a one-second threshold and let him by early, which I think could be a good idea. Some are not in favour. It's never going to be ideal. There are different opinions. Some want to keep the two-second mark, others want to go to a one-second mark. Everyone has got a different opinion.

"The problem is that it's a case-by-case thing and it's very tricky. It's very hard to police. I would be in favour of a shorted threshold but as soon as you see blue flags you have got more or less one lap to let the guy by.

"You know you are going to lose a second and a half because of a one-second gap and then half a second being behind but some places it's hard to get within one second, some others it's easy."