So beloved are Hong Kong’s red taxis that they’ve inspired t-shirts, art installations, and even recycled watches. But along with minibuses, the city’s taxis are responsible for up to 40% of certain kinds of roadside air pollution, says the government.

That makes the city’s fleet of 18,000 liquefied petroleum gas-powered taxis one of the biggest culprits behind the mask of white haze that often blankets Hong Kong’s skies and leaves pedestrians coughing. Now, through a mixture of carrots and sticks, the government—which already trains volunteers to spot and report dirty vehicles on the road—is moving more aggressively to try and lighten taxis’ pollution footprint.

There are two major problems that keep the city’s taxis trailing smoke, green groups say. One is the fact that 80% of taxis’ catalytic converters—which help filter up to 90% of emissions—are worn out, according to official figures. To tackle that problem, Hong Kong said this week it plans to launch a HK$150 million (US$19 million) subsidy program by Aug. 15 to help drivers get new devices, which the government says they should replace every 18 months.

The other problem, green groups say, is lax testing. Like all commercial vehicles, taxis in Hong Kong are required to undergo an annual roadworthiness test to stay licensed. But even vehicles with high levels of emissions have no problem passing the government’s test, which requires drivers to idle and then rev the engine for a designated period—something that doesn’t exactly mimic normal driving conditions.

“Even if the [catalytic] converter is not really working well, they can still pass [the test],” said a government spokesman.

Freda Fung of local think-tank Civic Exchange says the tests drivers have to pass in Hong Kong is also used by the European Union and in parts of the U.S. Still, she says, Hong Kong should do more.

“We have an urban setting that makes it less easy for pollution to disperse,” she says, citing the city’s densely packed maze of narrow streets and high rise buildings. “So we think we need to do more than other countries to improve air pollution.”

The government agrees. In addition to its subsidy program, it will implement more rigorous emissions tests, which it says will be “similar to a treadmill” and better-equipped for simulating real-world driving conditions. It will also deploy a system of cameras and remote sensing equipment across the territory from April to nab heavy polluters.

“They’ll move around the city, we’ll be doing it on rotation,” said the spokesman of such sensors, more than 100 of which are already scattered around the city for monitoring purposes. If caught on camera, drivers will need to have their vehicles tested by a stipulated date. Vehicles that fail the test will be taken off the road.

Taken altogether, Ms. Fung says, the government’s new efforts—which also includes restrictions on diesel commercial vehicles—should go a long way toward cleaning up Hong Kong’s skies. “It’s a generous program, but understandably generous,” she said of the subsidies in particular. “It’s only one time, and then everyone is clean … and knows the rules.”

via Hong Kong Taxis Drive Air Pollution – China Real Time Report – WSJ.