A bird's eye view of San Francisco, located on the West Coast of the US. (File photo)

Experience has proven that there is no such thing as "plain sailing" for seaports, such as San Francisco, New York, and Tokyo, to grow into world-class bay areas.

Like many rapidly-developing industrial cities, the three bay areas were once haunted by troubles including urban disease, migration, population boom, traffic, soaring house prices, environmental pollution, and the hollowing out of industry.

Many years ago, Tokyo was crowded and faced many problems including rocketing house prices, said Professor Marukawa Tomoo of the Institute of Social Sciences at the University of Tokyo.

As Stanley Kwong from the University of San Francisco noted, there was no Silicon Valley in San Francisco in the 1960s. But now, the San Francisco Bay Area, with Silicon Valley in the south, attracts many innovation resources, Kwong said.

Wall Street once relied heavily on the “invisible hand” which fueled a financial derivatives bubble, and finally led to the 2008 financial crisis, said Yiwen Yin, a former consultant at the World Bank Group.

There were always growing pains in the development process of the three world-class bay areas.

Meanwhile, the three bay areas have gained rich experience, and pressed ahead with a pioneering spirit and great achievements, which can provide a reference for other bay areas, including the Guangdong-Hong Kong-Macao Greater Bay Area.