Hanoi's fist BRT system was begun four years, and though authorities have sunk large amounts of money in it, has not worked well.

Dinh Thi Thanh Binh of the Hanoi University of Transport and Communications said, therefore, instead of expanding the costly BRT network, the city should trial buses-only lanes on wide roads.

According to the Hanoi transport master plan for until 2030, the BRT network is to have a total of eight routes.

"While the BRT carries more passengers than regular buses, it has not been operating at full capacity. The frequency of buses in many countries is one or two minutes but in Hanoi it is five to 10 minutes, which is below BRT standards," Binh told local media.

"This is due to narrow roads and other vehicles driving in the BRT lane, turning rapid buses into regular buses."

Having BRT systems that meet the World Bank’s standards is extremely difficult and expensive, she said. "Hanoi should opt for more suitable solutions."

The 14-kilometer BRT 01 route has already cost $53.6 million.

The other routes, which are to be much longer, should be carefully considered, according to some other experts.

Phan Le Binh, a lecturer at the Vietnam-Japan University and a consultant to the Japan International Cooperation Agency, said instead of rushing to add new BRT routes, Hanoi needs to earmark lanes exclusively for normal buses.

But Nguyen Trong Thong, chairman of the Hanoi Public Transport Association, dismissed the criticism saying the first BRT route could not develop alone and needs further connectivity to maximize its advantages.

"Compared to the metro, the BRT is cheap and flexible since its lane can be used for other purposes in case of inefficiency. Therefore, studies to expand BRT routes are necessary."

But Hanoi authorities first need to ensure the first BRT route meets the standards originally set out, he admitted.

According to the city Department of Transport, the BRT line, which runs from downtown Kim Ma Street to Yen Nghia District in the southwest, carried two million passengers in 2019.

BRT buses run at an average speed of 20 kilometers per hour, 30 percent faster than regular buses.

Hanoi's 2,000 regular buses carry around 1.2 million passengers a day, accounting for 12 percent of all commuters.