Each airport will have its specific no-toll timeframe, which will be decided by the government, said Vu The Phiet, General Director of the Airports Corporation of Vietnam (ACV), which manages 21 civilian airports in the country.

ACV is currently upgrading systems to collect fees digitally, including the function to record the time cars enter and leave the airports.

For instance, cars entering and leaving Tan Son Nhat or Noi Bai airports will have their license plates photographed while entering. When leaving, if the cars are still within their allowed timeframe, the barrier at the fee collection point will lift on its own, otherwise the cars will have to pay to exit, Phiet said.

Currently, cars are charged VND15,000 ($0.65) for the first 60 minutes after they enter the airports, and VND5,000 ($0.22) for every 30 minutes thereafter.