There are many other shock advertisements with a public-safety message, showing China's lax approach compared to more developed markets, according to a marketing professor.
China's shock adverts use graphic pictures of Princess Diana car crash
BEIJING // Beside a motorway between Nanjing and Shanghai, the billboard was nothing if not attention-grabbing: it showed a graphic photograph of Princess Diana's body as rescue workers tried in vain to save her after a car crash.
With Chinese characters in bold red type, it warned "misfortune does befall us sometimes" and in a poignant twist: "It doesn't differentiate its prey: even a princess couldn't be spared."
The photograph on the billboard appeared on the internet after the 1997 crash that killed Diana and is believed to be fake. But it is unclear whether the authority that produced the hoarding, the Hu Ning Expressway Division of the Nanjing Traffic Police, knew this.
Underneath the horrific image of the stricken princess, which is made more shocking by its juxtaposition with a photo of a smiling Diana, are the words: "Value your life, safety always comes first."
It is unsurprising that officials in China use shock tactics to improve road safety. According to police statistics, which even state media say heavily underestimate reality, 70,000 people were killed on the country's roads in 2009.
Figures from death registrations suggest the actual death toll could be more than three times higher. By comparison, an estimated 32,788 people were killed in traffic accidents in the United States in 2010. The US has less than one-third the population of China.
There are many other shock advertisements with a public-safety message.
No less graphic than the Diana billboard are those put up around Chinese New Year to warn of the dangers of fireworks that are let off as part of the festival.
Occasionally political tensions result in controversial advertisements. In January, a Hong Kong newspaper, Apple Daily, made waves by publishing a full-page advertisement showing a giant locust overlooking the special administrative region,
The locust represented the 40,000 women from mainland China who travel to Hong Kong each year to give birth so their children gain residency rights.
Advertisements in China sometimes reflect ethical and professional standards that are "a little more lax" compared with more developed markets, according to Chiang Jeongwen, a professor of marketing at the China Europe International Business School in Shanghai. Those producing the billboards or advertisements think shocking imagery or wording is "not a big deal".
"In China the advertisers will quite often try to use these kinds of sensational graphics or some kind of wording to try to get attention," he added.
While shock adverts are used to promote road safety, cigarette producers do not however have to use graphic images on packets, to the frustration of campaigners who suggest there is official reluctance to combat smoking because of the huge tax revenues generated by the tobacco industry.
Shock tactics used in Chinese advertisements could be seen as following a trend pioneered by western advertising agencies, they also have echoes in China's own past.
During the Cultural Revolution, the chaotic period that began in 1966, the then leader, Mao Zedong, released propaganda posters castigating his rivals that were no less dramatic than the most hard-hitting modern-day billboards.
One showed the president, Liu Shaoqi, who was expelled from the Communist Party and who died after being denied treatment for his medical conditions, being shovelled like a pile of dirt.
In the present day, the Chinese authorities have shown a willingness to rein in advertisers. In 2007 they outlawed "sexually suggestive" television and radio advertisements, including those featuring underwear and drugs linked to sexual performance, reported the state-run Xinhua news agency.
Last year, Beijing municipality officials banned advertisements from using words such as "high class" or "luxury" because of concerns that these could inflame anger among poorer residents over the growing wealth gap.
Despite these efforts, which experts say are compromised by China's obligations linked to its World Trade Organisation accession, more subtle social trends are nonetheless evident.
"For advertising showing children or adolescents, it used to be they were always obedient, studying, good to their parents, these very traditional values," said Kineta Hung, an associate professor in the department of communications studies at Hong Kong Baptist University.
"[Now] you're seeing kids that are bolder, they stand up more and their less traditional."