FIA tightens track limits rules for Formula 1's Mexican Grand Prix

On the first lap last year, Lewis Hamilton cut across the grass after running wide at Turn 1 and rejoined the circuit still in the lead.

Race stewards did not believe he had gained a lasting advantage from the incident, so did not order him to concede position to Nico Rosberg.

There was bigger controversy later when Max Verstappen ran across the grass in an identical way while defending against Sebastian Vettel.

Verstappen went on to take third place on the road, but was handed a penalty post-race - dropping him off the podium - because stewards felt he had unfairly benefited.

With track limits a big talking point following Verstappen's penalty for cutting the track at Austin when he overtook Kimi Raikkonen on the final lap, the FIA has moved to ensure that hard and fast rules are in place at Turn 1 at Mexico City.

Speed bumps, which are 50mm high, have been installed on the left hand kerb between Turns 1 and 2, with a second series of them situated between Turns 2 and 3.

In a note sent by F1 race director Charlie Whiting to teams ahead of the Mexican race, he has made clear that drivers will now have to go around the second series of speed bumps before they rejoin the track - which in theory will cost them time.

"For safety reasons, any driver who either passes to the left of or runs over the orange kerb sections on the driver's left between Turns 1 and 2, or who passes to the left of the bollard on the apex of Turn 2, must rejoin the track by driving around the end of the orange kerb sections on the driver's left between Turns 2 and 3," Whiting wrote.

Further limits have been placed at Turns 8 and 11, where other speed bumps have been put down.

Whiting added: "For safety reasons, any driver whose car passes completely behind the kerb on the apex of Turn 8 must rejoin the track by keeping wholly to the right of the orange kerb parallel to the track on the exit of the corner.

"For safety reasons, any driver whose car passes completely behind the kerb on the apex of Turn 11 must rejoin the track by keeping wholly to the left of the orange kerb parallel to the track on the exit of the corner."