The much ridiculed proposal by a former town planner to improve traffic in Central by stopping tram services has been flatly rejected. This will come as a relief to conservationists and also please the public. But the problem of traffic congestion, not only in the central business district but in other busy commercial areas, including Causeway Bay and Mong Kok, remains as pressing as ever.

Slow moving cars clogging the streets in these areas are creating an even greater headache - air pollution. This poses a major threat to public health. Building more roads and flyovers has done little to ease the traffic jam. And there is a limit to what traffic control can do to cope with the explosive growth in the number of vehicles on the road.

Even an excellent public transport system has failed to persuade enough people to leave their cars at home when going to commercial districts to work or to entertain. Nor have they been discouraged by limited parking space in these districts.

All is not hopeless, according to Calvin Kan, a planning and development executive at international real estate agent Knight Frank. His proposal, expressed in a South China Morning Post commentary, called for the creation of more pedestrian-only zones in the busy commercial district. But this is not a new idea. Many environmentalists and city planners have made similar suggestions in the past.

The concept, though sound, was vigorously opposed by business people who were afraid that a ban on cars would cause serious disruption to customer traffic and logistics. They just don't want to see any drastic change to an environment they are used to.

But it is worthwhile for the government to reconsider the idea, which has worked exceedingly well in major cities in the United States and Europe. Citing examples in overseas cities, Kan noted in his article that 20 percent to 60 percent of traffic disappeared where roads were closed or traffic capacity was reduced.

This is a significant issue which addresses concerns that the closure of some roads in one district would only cause even greater congestion on other roads in the same district. Experiences in other cities have shown that road "closures did not result in the re-routing of traffic as in liquid form, but contracted as if traffic behaved as gas," Kan wrote.

The benefits of road closures to vehicle traffic were clearly demonstrated in New York. After closing a portion of Broadway for six months in 2009, city planners were astounded to find that pollutants related to traffic emission were down by as much as 63 percent. As a result, the city authorities are planning to expand the pedestrian zone on Broadway.

Such compelling evidence means the Hong Kong government has to give the idea a try. If people get tired of walking, they can always hop onto the trusted trams that will take them to wherever they want to go without doing any harm to the environment.

(HK Edition 10/29/2015 page7)