Planners need to end the occupation of our streets - by vehicles

The Occupy movement has done more than disrupt and cause inconvenience; it has provided an invaluable chance to rethink what is needed to make our streets more friendly to pedestrians and the environment.

It is not surprising that the air quality in Central, Causeway Bay and Mong Kok improved remarkably during the occupation period, since people could walk, run or even bike instead of suffering the usual traffic crawling along roads at peak hours.

We collected data of concentrations of fine particles (PM2.5) at the three occupied areas on October 1 and October 15, and found that on October 1, all three locations showed lower concentrations of PM2.5 comparable with the World Health Organisation benchmark, indicating an improvement in air quality.

However, after police partially cleared barriers and reopened roads in Causeway Bay and Central, the concentration of PM2.5 pollutants rose; the October 15 readings showed an increase of 225 per cent in Causeway Bay and 244 per cent in Central. In Mong Kok, where roads remained closed, PM2.5 levels rose by 161 per cent. Since we believe ambient air quality was worse that day, Mong Kok served as a control variable.

Although the government claimed that the partial clearance of occupied areas could alleviate congestion, there have been serious jams after roads were reopened. Clearly, the government should consider fundamental changes to its transport policy.

People around the occupied areas have begun to rethink their spatial perceptions. For instance, a commuter running from home in Western district could get to work in Admiralty in 15 minutes less than it would take by bus. This shows it would be viable to set up pedestrian zones in core commercial areas.