Anyone with a chest under 28 inches will be banned
from driving a motorbike - which make up 90 per cent of the traffic on the country's chaotic roads.

Anyone who is too short, too thin or too sickly will also have to seek alternative transport. Ailments such as enlarged livers or sinusitis will rule out aspirant motorists.

"The new proposals are very funny, but many Vietnamese people could become the victim of this joke," said Le Quang Minh, 31, a Hanoi stockbroker. "Many Vietnamese women have small chests. I have many friends who won't meet these criteria."

The average Vietnamese man is 5 feet, 4 inches (164 centimeters) tall and weighs 121 pounds (55 kilograms). The average Vietnamese woman is 5 feet, 1 inch (155 centimeters) tall and weighs 103 pounds (47 kilograms).

Vietnamese bloggers have been poking fun at the plan, envisioning traffic police with tape measures eagerly pulling over female drivers to measure their chests.

"From now on, padded bras will be best-sellers," said Bo Cu Hung, a popular Ho Chi Minh City blogger.

"I'm not heavy enough, what am I going to do?" Le Thu Huong asked in a letter to Tuoi Tre newspaper. "And what about people whose chests are small? Most of them are too poor to afford breast implants!"

Vietnamese roads are among the most dangerous in the world but it is not clear why the ruling Communist Party believes banning small drivers will make them safer.