The system of slow zone caution areas used at the Le Mans 24 Hours has been modified for this year's race.
There will now be nine predetermined slow zones around the 8.47-mile circuit in which the cars can be limited to 80km/h under virtual safety car conditions.
There had previously been no set starting point for the slow zones since the introduction of the system in 2015: they ran between marshals posts chosen by race control on a case-by-case basis when incidents occurred around the track.
Vincent Beaumesnil, sporting director of Le Mans organiser the Automobile Club de l'Ouest, told Autosport: "The drivers had concerns about the previous way we did it, because sometimes they were slowing down to 80km/h in very fast areas of the track.
"We decided that we should have fixed slow zones and that the starting point should be in a low-speed area where the cars are accelerating.
"The only exception is the one that starts at the beginning of the Porsche Curves, because we didn't want one slow zone all the way from Arnage to the end of the Porsche section."
Beaumesnil explained that the new system had not received any complaints and had worked when trialed during last weekend's official pre-race test.
"We have spoken to the teams and drivers, and they are positive about the changes," he said.
"There were no concerns when we presented the idea, and from what we experienced it the test, it seems to work."
There could be further evolution of the slow zone concept at Le Mans, according to Beaumesnil, who reiterated the ACO's belief that slow zones are preferable to regular use of the safety car to deal with an incident.
"We started with slow zones three years ago and are improving each year," he added.
"If there is a choice between a slow zone and a safety car while, for example, a barrier is repaired, it is an easy decision."
The new system had been communicated to the teams earlier in the year and then discussed in detail in the drivers' briefing ahead of Sunday's test.