Due to the nature of the Monaco Street Circuit, FIA Formula 2 changes their usual Qualifying format to avoid issues under traffic.
A lap around Monaco in a Formula 2 car is extremely short and the walls are never too far away. This means all of the cars are likely to be close together with little or no space to move out of the way of those on a flying lap.
To avoid any issues (impeded laps or collisions) the session will be split into two parts. Those who race with even numbers will take part in the first session at 15:10-15:24, local time (CEST).
Those who race under an odd number will qualify in the second half of the session at 15:34-15:48 (CEST).
No group should face an unfair advantage surrounding grip levels or track temperature since the times of each session will not be compared to make the grid.
Instead, each group will start on a different side of the grid. Whoever is fastest between both groups will start on pole, whoever is fastest in the other group will start second on the grid. The rest of the grid will follow the same pattern.
It helps to reduce the risk of crashes by minimising the number of cars on track since closing speeds are a common issue at many circuits like Monaco during Qualifying. It also gives all of the drivers more of a chance to put a lap in.
This is a format that was talked about often for different series and tracks when it was first introduced and is usually mentioned again around Monza Qualifying.
Image; Formula Motorsport Limited