The 500-meter-long Tian'ai Road in Shanghai's Hongkou district has been named as the city's most romantic road, as flocks of lovebirds scrawl their names and sweet nothings on the wall and ground along the street.

Part of the street's association with amore is its name: Tian'ai translates as "sweet love".

And many people believe that if a couple walks the entire street, the couple's relationship will be blessed with happiness forever.

"We usually take about half an hour to walk on this street," 21-year-old Zhang Qiqi, who moved to Shanghai with her boyfriend two years ago, says.

"It's perfect for people in love."

Many messages scrawled on the walls seem childish, perhaps, but sweet, nonetheless. Take "Qingqing loves Chenchen forever!" as Exhibit A.

The walls that create the canvas for smitten graffiti - 28 love poems have been carved into, or painted on, the walls - also offer some seclusion. And Tian'ai cafe, which takes its namesake from the street, has developed a reputation as an ideal place for lovers to chat over a cuppa.

An online survey circulated on Sina Weibo - China's answer to Twitter - finds more than half of respondents support the graffiti. Some residents have proposed the construction of a love wall to allow more couples to express their affections in writing.

But the local supervision department forbids graffiti and covers up most messages soon after they're written.

Hongkou district publicity department employee Wang Wei says the writings are removed because they're unauthorized.

Some netizens argue authorities' approach is too inflexible, and the local supervision department could use the street's name and reputation to promote it as a sightseeing landmark.

"Why can't we learn from foreign countries, where graffiti is considered pop culture," a netizen called lovemok says.

But not everyone agrees.

"I don't feel comfortable living on a street with these riffraff," says a 63-year-old woman, surnamed Fang, who has lived near Tian'ai for more than 15 years.

"I can understand these young people, but I want a tidy street more."

Another nuisance to residents is the street's popularity has led to a boom in love-related businesses, such as wedding photography studios.

"It's pretty annoying, but there's nothing we can do about it," Fang says.

Online retailers have discovered people will pay extra for a postcard stamped with a unique Tian'ai Road mark, even though the stamp can be obtained for free from the subdistrict office of North Sichuan Road, which is responsible for managing Tianai Road.

So online vendors buy postcards and line up to get the stamps, especially around Valentine's Day.

The postcards sell for about 5 yuan (79 US cents), and sales are brisk.

"The postcard stamps mean we're getting busier, especially around Feb 14," an office staff member, who didn't want to be named, says.

"We're not encouraging people to sell the postcards, but we can't refuse to give the stamps."