The minimum distance for vehicles following the rider has been changed from 10 metres to 25 metres.

"This new rule aims to ensure that the results of time trials are not influenced by the proximity of the rider to the following vehicle and thus to guarantee the sporting fairness of the competition and increase rider safety,” the UCI said.

The changes have been made after research by the University of Eindhoven established that placing vehicles close to the cyclist can modify the air flow around the rider and "potentially lead to an advantage gain for the cyclist."

Researchers found that a car travelling ten metres behind gives the cyclist an advantage of 0.05 seconds per kilometre when travelling at 46.8 kilometres per hour, the typical speed achieved in time trials.

The advantage became insignificant at 15 metres but after consultation, it was decided to extend the prescribed distance between the vehicles and rider to 25 metres.

This was also done to ensure greater safety to riders by allowing the drivers of vehicles longer reaction times in the event of unexpected incidents.

Other convoy vehicles such as commissaires, regulators, television motorbikes and photographers are permitted to stay closer but must remain out of the direct slipstream of riders.

Stricter regulations on dangerous driving have also been introduced.

Photographers will also be liable for the actions of their motorcycle riders and dangerous actions will be subject to a fine and suspension of up to seven days for the photographer, an alteration to previous regulations which only sanctioned the rider of the motorcycle.

Regulations have also been modified to allow the adjustment of time trial handlebar extensions.

"The objective of the new regulations is to provide riders with greater stability and safety while maintaining an aerodynamic position," the UCI explained.