Wang says he was impressed by the Crown Fountain in Chicago's Millennium Park, which shows ordinary people's faces on big LED screens when the fountains erupt.

In response, his team designed a work called Beijing Memory at the Line 8 station of Nanluoguxiang, which is well known for its hutong. A portrait of people's lives is made up of hundreds of glazed tiles, in which he plans to embed an article of daily use.

"It doesn't matter whether it is a teapot or a sewing machine component," Wang explains. "What matters is that it represents our collective memory. Taking the subway is not only traveling through space, but also through time."

Though it is common to see these old items in antique markets, he expects ordinary Beijingers to donate their own pieces.

"You can imagine how excited one might feel when one's belongings are displayed in public," Wang says excitedly.

Wang's team has many other ideas, like a painting of rippling waters that changes according to the angle. Some ideas, however, were vetoed because of safety concerns.

"The subway authorities would not allow us to install various electric cables or use some kinds of materials," says Wu Dingyu, the designer at Guloudajie Station. "And the space left for our creations is still limited."

However, Wu is glad artists now have more say in the design of the capital's subway.

Contact the writer at wangkaihao@chinadaily.com.cn.