In his more than two years in Hanoi it was not the first time the 24-year-old Chinese had seen people drunk like this.

Once, after a party, a Vietnamese woman friend insisted on riding him home though very drunk. He says: "She was going in the opposite direction and staggering, and I was very scared sitting at the back. After a short while I said I will ride." 

Since then he has hardly gone out to drink with friends, and always gets a motorbike taxi if he does. 

Now that the Law on Alcohol Harm Prevention and Control and Decree 100 on fines for drunk driving have been passed, Lee hopes his Vietnamese friends will comply to ensure their safety as well as others’.

The decree, which took effect on January 1, imposes stiff penalties for drunk driving. 

Riding cycles and electric bicycles under the influence now faces fines. Motorcyclists and car drivers can be fined VND6-8 million and VND30-40 million ($1,300-1,725), double the old levels and have their licenses suspended for 22-24 months.

For the last two weeks Lee has seen a considerable change, with the pubs near his house being less crowded and noisy and fewer cases of drunk driving occurring. 

"At the year-end party on January 1, nobody in my company touched a drop of alcohol." He works for a law firm in Dong Da District. 

He says in his country drunk drivers can be fined 1000-2000 yuan ($145.25- 290.50) and have their driving licenses suspended for six months. 

In case of an accident after drinking, the driver faces a criminal charge and permanent loss of their license.

Takuya Okazaki, a 26-year-old Japanese designer living in Ba Dinh District, says: "In the last two weeks my colleagues have not asked me to go out to drink. Last Sunday I went to Ta Hien Street and found the number of Vietnamese customers had decreased dramatically." 

Since coming to Vietnam in 2016 he has admittedly enjoyed the Vietnamese drinking culture. 

"Vietnamese drink while shaking hands, making everyone feel connected. Moreover, when drinking, there seems to be no hierarchy like in Japan." 

But he admits Vietnamese tend to drink too much. "Every week I go out and drink one or two times, but my Vietnamese colleagues drink four or five times. They even say ‘not drunk, don’t go home’." 

Like Yi's friends, his colleagues too go home by motorbike after drinking. At first he used to be very worried about them, but stopped saying anything since no one listened to his warnings. Once he saw a motorbike accident caused by a drunk person, and told himself to be even more careful. 

Takuya learned about Decree 100 from the media. "I strongly support this law because it will improve people's awareness." 

Japan has long had laws against drunk driving which go up to five years in prison and a fine of one million yen ($9,089).

Frenchman Julien Psomas, 38, a lecturer at a university in Hung Yen Province, says, "Decree 100 is the best thing the Vietnamese government could have done to minimize accidents on the road." 

He has lived in Vietnam for four years. Though he has never seen one himself, he still knows about the high rate of alcohol-related accidents from the media.

Like Okazaki, he too thinks Vietnamese drink too much. "They drink till they are drunk" and most are careless and drive home themselves, he says. 

He says he only drinks once a week, and takes a taxi if he drinks in a pub. 

In France, to drive a vehicle, a person’s blood alcohol level must be below 0.5g/l. If they have less than three years’ driving experience the limit is 0.2g/l. 

Anything above these attracts a fine and gets points deducted from the driver’s license. If the blood alcohol concentration level is above 0.08 percent, the driver faces a criminal charge, a fine of 4,500 euros, a three-year suspension of the license and a two-year prison term. 

"Taxis in Vietnam are not so expensive that you cannot call one to go home after drinking," Psomas says. 

"Next year I hope there will be more laws banning driving while using phones."

Ye Min He, 50, a South Korean who works as a real estate investment consultant in Hanoi, says Decree 100 applies not only to Vietnamese but also foreigners. 

He came to Vietnam seven years ago. Due to the nature of his work, he has driven motorbikes and cars many times after drinking. "Once my eyes were heavy due to alcohol, but I still drove from Hai Phong to Hanoi (some 100 kms)."

Before Decree 100 came, he would drink a bottle of beer or at least half a bottle during lunch every day. Since January 1, warned by friends and colleagues about the decree, he has stopped though he only has to drive around 200 meters.

"In the first few days lunch without beer was very boring. But I must get used to it."