Devi Asmarani, Jakarta – The idea was to ease traffic along Jakarta's busiest streets by encouraging people to abandon their cars, but a new bus system due to start running next month is already causing headaches.

Round-the-clock construction of the 120 billion rupiah project to lure commuters onto special luxury buses which will zip along in their own lane has compounded traffic congestion in the heart of the capital. A stretch of road normally covered in about 15 minutes now takes at least an hour.

The 12.9km bus lane starts at the major bus terminal in the Blok M district and runs through Jakarta's most prominent streets, where most of the high-rise office buildings are located. The route stops in the hectic Chinatown (Kota) area.

A fleet of 56 new buses will drop and pick up passengers at shelters being built on the central median strip.

Jakarta Governor Sutiyoso has argued that when the buses begin operating, traffic flow will improve as hundreds of buses now using the same route will no longer operate there.

But there are more sceptics than believers. Most fear that with one lane off-limits to private cars and taxis, traffic jams in the city of 4.7 million vehicles, and growing at the rate of 8 per cent a year, will only get worse.

A recent survey by the Japan International Cooperation Agency showed that peak-hour gridlock caused annual economic losses of some 5.5 trillion rupiah.

Critics of the plan say new air-conditioned buses are unlikely to persuade Jakarta residents to leave their cars at home. For one thing, the bus route is limited to the Blok M-Kota area, so commuters from the surrounding suburbs or boroughs will still have to find ways to get from their homes to the nearest busway terminal.

With a capacity of 81 passengers, the new buses are also unlikely to be able to cope with some 50,000 people travelling the stretch of roads every day.

Already under fire for evicting thousands of poor residents from city slums, the governor's office has been slammed for not anticipating the problems the bus plan would create.

As a result, new policies will be introduced to support the busway system. These include expanding an existing ban on vehicles with fewer than three passengers from entering downtown during the morning rush hour. The new ban will last till early evening.

The city administration is also considering allowing vehicles with certain plate numbers to enter downtown on certain days.

"All these show that the government has no clear masterplan," Mr Asad Nugroho of non-governmental organisation the Public Interest Research and Advocacy told The Straits Times.