Formula Three qualifying had to be halted on Friday for safety reasons after a queue of cars lined up on the back straight preparing to start their timed runs while others approached at speed.
Safety in the support series to Formula One is under increased scrutiny after the events of Spa-Francorchamps last Saturday.
Hubert, 22, died after his car was hit at speed by Juan Manuel Correa's after the French driver had gone off into the barriers at Spa's fast Raidillon corner.
American-Ecuadorian Correa is on life support and in an induced coma in a London hospital.
Hubert was the first driver fatality at a Formula One race weekend since Ayrton Senna and Roland Ratzenberger were killed at Imola in 1994.