Recently, an elderly minibus driver suffered heatstroke and fell unconscious after he switched off his engine, and hence the air conditioning, while waiting to pick up passengers. He died later in hospital. It was discovered that the temperature inside his vehicle was 41 degrees Celsius. There was a similar case involving a double-decker bus driver who, fortunately, survived.
There have been numerous heatstroke incidents as a result of the recent sweltering weather. This week has seen the hottest day of the year so far, with the temperature topping 38 degrees in some parts of the New Territories. We all know that the summer weather in Hong Kong is unbearably hot and humid.
A proposed statutory ban that requires drivers to switch off idling engines as a way to reduce the city's air pollution, especially in densely populated districts such as Causeway Bay and Mong Kok, is a good environmental policy in principle. But it is not practical to implement here.
First, it is inhumane to force professional drivers to sit in a car with no air conditioning in sweltering heat.
Second, the ban will not work for private car owners, especially those with chauffeurs, who can simply drive the vehicle around while waiting for their bosses. Not only will this worsen the air quality and add to congestion - particularly in Central - it will also create a class division and social conflict. It will create a situation in which the poor and powerless will be restricted by the law while the rich and powerful will be exempt.
So what's going on here? The fact is that we have simply borrowed the concept from overseas without due consideration as to whether it is suitable for Hong Kong.
We have to understand that, even in overseas jurisdictions, similar idling-engine bans are enforced effectively because they make room for reasonable exemptions to suit changing circumstances. Take Toronto as an example. In extreme weather conditions, either when it is too cold or too hot, the engine ban is temporarily suspended.
However, our environment chief Edward Yau Tang-wah, who wants to push the ban through as quickly as possible, said further exemption clauses would only dilute the spirit of the law, rendering the ban ineffective.
No matter how we look at the ban, it will ultimately be rendered ineffective because people will always find a way to circumvent the rules.
For environmental policies to be effective, we need to have the people's best interests at heart and ensure legislation is practical and enforceable. The most effective way to change people's behaviour is through public education. Hong Kong citizens are relatively civic-minded and can be easily mobilised to support a common cause, especially if it benefits society at large. Community campaigns - such as those that targeted spitting and littering - have been successful.
Through public education, supported by a strong publicity drive, people will learn to automatically switch off their car engine when the situation allows. The whole idea is to turn this into a natural habit, rather than force people to comply.
If the government manages to push through the ban, imagine what the impact will be on tourism in the summer: with no air conditioning to lower the interior temperature on buses, do you think tourists will put up with these oven-like conditions after hours of shopping and sightseeing?
The ban will bring more harm than good. The only positive outcome is that it may increase the demand for chauffeurs, creating more jobs. Other than that, I think it's time Yau turned his campaign engine off instead.
Albert Cheng King-hon is a political commentator. email@example.com