Despite the appeal of public transportation in the Chinese capital, private vehicles remain many residents' first choice for getting around.

"It's horribly crowded in the subway and hard to be on time when taking the bus," said Hu Yanrong, a 32-year-old consultant who drives 18 kilometers to her office every day. "We all know car exhaust contributes to the haze, but it's too exhausting to take a bus to work every day.

"No one wants to make the pollution worse, but you can't sacrifice your career either."

Hu said the government is neglecting its responsibilities by making it the obligation of residents to improve air quality while depriving them of the right to drive.

On Monday, the capital maintained its orange pollution alert, the second-highest level, and severe smog is forecast to linger in Beijing until Thursday.

The concentration of PM2.5 in Beijing soared on Sunday night, the government said. PM2.5 is particulate matter with a diameter less than 2.5 micrometers, a major contributor to the smog.

Beijing Commission of Transport data put this weekend's traffic index at the second-lowest of the past 10 weekends, showing that traffic congestion — or the amount of private vehicles on the road — was significantly reduced.

The commission said the index is based on the average speed of the city's more than 60,000 taxis. An index of 0 to 4 suggests smooth traffic, 4 to 6 reflects slight congestion, 6 to 8 severe congestion, and 8 to 10 the highest congestion.

The real-time traffic index reached no higher than 3.9 last weekend, while most other weekends reached no lower than 5.

But the index increased sharply on Monday to 6.1 during rush hour at about 8 am, making it the third-most-crowded Monday this year.

A commission insider said the reduced traffic over the weekend and increased traffic on Monday indicate that when people need to get around, private vehicles remain their first choice.

"Most people stayed away from the outdoors last weekend because smog clung to the city for days in a row, but when people need to get to work, most still use their own vehicles," Hu said.

The commission said the government will further enlarge the city's public transportation system to attract more commuters and reduce the amount of exhaust emissions from private vehicles.

Stay inside

In response to the lingering smog, the government has advised children and the elderly to stay indoors and wear masks when outside. Kindergartens and primary and middle schools were advised to reduce outdoor activities.

The city has ordered 36 companies to halt production and another 75 to reduce it as part an emergency response plan.

Meanwhile, subway Line 5 broke down on Monday morning because of signal failure, making many commuters late for work.

It is not the first time the city's subway system has broken down. Heavy passenger volume has caused signal failures in the past year, which in turn have forced the subway to suspend operation, delaying thousands of commuters.

The city aims to have the subway cover more of the capital to further ease the demand for public transportation.

Beijing will also unveil its first monorail this year to ease traffic in the southwestern part of the city.

The 24-km Yuquanlu Line, with 21 stations, is undergoing an environmental impact assessment, and will attract more passengers from crowded subway lines in the main urban area, the China Academy of Railway Sciences said.