ZHAO Jiaqiang, a part-time designated driver, was very busy over the National Day holiday, soberly driving his intoxicated customers home from dinners, karaoke or clubbing.

They were smart enough to know they would drink too much and shouldn't drive, and they didn't want to leave their cars in parking lots while they partied. So Zhao, in his 40s, drove them to and from parties.

Drunken driving and driving while intoxicated is a serious problem in China, as in other countries.

Since mid-August, Chinese traffic police - including those in Shanghai - have seriously cracked down on tipsy drivers. Those with high blood alcohol are to be detained immediately for 15 days. That used to be the upper limit of punishment, seldom enforced.

Maximum fines and license suspensions are imposed.

All over the country in major cities, traffic police set up checkpoints on major roads and near big restaurants and clubs at night to check private cars.

So serious is the enforcement in Shanghai (according to one man who was just released) that cops confiscated his cell phone so he couldn't call someone to pull strings and get him released.

In the past many people never worried about driving while drunk because they were seldom punished severely. Now they're scared.

More of them are calling taxis and some are getting designated drivers, which has created a business spark. People seldom take a non-drinking pal along to parties; everybody drinks.

Although some small drivers' agencies provide services for intoxicated drivers, most drivers like Zhao are freelancers. He works for a drivers' agency during the day and clients know him.

In most cases, there is no contract; the going rate is 50-100 yuan (US$7.32-14.64) each ride.

Zhao charges about 70 yuan for 10-kilometer job and he got two or three jobs every night during the golden week.

But he only takes jobs from returning customers and doesn't consider expanding.

"It's a great way to make additional money at night," says Zhao, "but it's also rather dangerous.

"You never know what a drunk person will do, especially if they are strangers. Sometimes, my customers are so drunk that they can't even tell me the correct address. Luckily I know their home addresses because they are also my daytime customers."

It's also a pain to have to wait for customers who set a pick-up time, but stay on and party.

"Sometimes people are really picky about others driving their cars. They just don't like anything you do, even though I drive carefully," says Zhao.

On the other hand, many car owners who like to drink are also concerned about turning the wheel over to a designated driver.

"The service sounds great and it's exactly what people like me need, but it's still quite inconvenient and expensive," says 28-year-old sales manager William Wang. "I'll wait until the business gets more mature."

Meantime, he continues to drink and drive.

Wang needs to take customers out to dinner every two or three days and often must drink.

Confident, like most drinkers, that he can handle his liquor, Wang used to drive home even after just a few drinks. But he got scared after two friends got caught in September - and put in detention for 15 days. He called a designated driver that his friend had used.

"Being driven home made me just as anxious as I would be if I were driving myself after drinking," Wang says, adding that he worried the driver might get into an accident or damage his car - that bothered him more than getting caught by police while intoxicated.

Others share Wang's concerns about price, insurance, the designated driver's skill and the safety of their belongings in the car.

"My car is like my second apartment and I just leave a lot of stuff in it - toys, watch, cash, bills, and so on," says 32-year-old businessman John Wu. "I know it's bad to suspect others, but it's also dangerous to completely trust strangers. What if the driver steals my belongings when I'm really drunk? Or maybe even robs me?"

He says he would lock all his possessions in the car's trunk before calling a designated driver - and would only call one if he wasn't too drunk.

China is strictly enforcing its laws against drunk driving - 15-day detention and other punishments were already on the books, but as upper limits. Seldom were maximum penalties meted out. Today they are.

After two months of rigorous enforcement since mid-August, authorities are now considering punishment of passengers in a car driven by a person who is intoxicated or outright drunk.

The decision on tough enforcement followed three deadly accidents around the country that claimed 10 lives, injured five others, including children, and shocked the nation. The crashed claimed the lives of a couple with the wife being pregnant.

In each case (in Hangzhou, Zhejiang Province, Nanjing, Jiangsu Province and Chengdu, Sichuan Province), a drunken driver was responsible.

This is a summary of the law: There are two offenses, depending on blood alcohol levels: driving while intoxicated (DWI) and drunk/intoxicated driving.

Someone is DWI if blood alcohol, according to a breathalizer test, is 0.2mg/ml or above, but under 0.8. A level of 0.2 is roughly equivalent to a large glass of beer and 0.8 is about two or three shots of distilled spirit.

Since August 15, traffic departments in most major cities in China are applying the upper limit of punishment to all these drivers who are stopped.

DWIs lose their license for three months and are fined 500 yuan (US$73).

Drunk drivers are detained immediately for 15 days, fined 2,000 yuan and lose their license for six months.

Anyone who commits two violations in one year will lose their license permanently and are not permitted to apply for a new license for two years. All the other penalties apply.

Since mid-August, it's been 15 days behind bars for drunk drivers who fail their breathalizer test. It's supposed to be right away, no exceptions.

A night club owner in Ningbo, Zhejiang Province, with the Net name A Jian is one of the hundreds of intoxicated drivers stopped over the past two months in Shanghai.

He got thousands of clicks and responses after he posted a 15-day diary written on tissue paper while under custody. He posted it on his blog when he was released.

Caught and confined on September 4, A Jian lost a few contracts during the 15 days and estimates he lost 100,000 yuan (US$14,650). Locked with nearly 20 people (detained for various offenses and not all white collars) in the same room, A Jian borrowed a pen from the police and wrote his diary on tissue paper. Detainees are not allowed regular writing paper. The 15-day diary of nearly 6,000 words filled 30 tissues.

September 5

I was put in detention at 4pm. What a strange place. I would have never imagined myself getting here in my whole life. I had to have my booking photo taken, just like criminals in movies. I felt really bad to get treated like this because I only drank some beer. Then I was taken to my cell, filled with a lot of people.

September 16

I've been anxious for the whole day, as my release is approaching. I feel more and more homesick and can't stand it for even one more second. I have never been in the same bed with 16 people in my whole life. How bitter!

September 19

This is the longest day just before I get out. Somehow I get through, I can't describe my feelings. I'm excited.

After release

After the whole 15 days, I realize how silly it is to drive while intoxicated. It cost me my freedom, affected my business and I couldn't take care of my family. I promise not to drink and drive from now on.