BEIJING (China Daily/Asia News Network) - The "straddling" bus is just for tourism rather than for transport, the authorities in China's northern city of Qinhuangdao have said, after the media cast doubt on the feasibility of the futuristic vehicle.

The 22m-long bus, whose carriage is elevated above the road to allow vehicles to zip pass underneath, took its first road test in the seaside city last Tuesday.

But Chinese media and netizens soon started asking many questions: How would the bus negotiate turns? What about the many drivers who jump in and out of lanes? And what about vehicles like trucks that are too large to fit under the bus?

Several media reports even claimed that it was nothing but a gimmick to sell fund-raising products.

Amid the whirlwind of controversy and heated discussion, Zhai Wen, head of transport division of the municipal development and reform commission of Qinhuangdao, told China National Radio (CNR) that the road test of the bus, named TEB-1 ,was merely carried out "for tourism".

The test was conducted on a 300m part of a dead-end highway near Beidaihe village, said Zhai.

Dong Xin, one of those who was aboard the bus during the test drive, expressed his disappointment to CNR, saying that TEB-1 ran only about 50m, and at low speed.

He also complained that the bus' enclosed carriage was too hot, as the air-conditioning was not turned on.

According to TEB Tech, the bus' maker, the "full version" of the bus will reportedly be 60m long, 7.8m wide and 4.8m high. It will be capable of carrying 1,200 to 1,400 passengers and run at an average speed of 40 kmh.

The vehicle is advertised as a solution to traffic congestion.

However, senior engineers in automotive engineering development at the prestigious Tsinghua University expressed doubt over its efficacy, as such a huge vehicle will need to move slowly in case of emergency braking.

Other limitations raised by transport experts such as Yang Tao, head of Nanjing Institute of City and Transport Planning, include current road limitations and traffic rules.

According to China's design code for road construction, the general height limit for vehicles is 4.5m while under-bridge height limit on main roads is 4.2m.

Costly works would be required to make TEB a reality. Pedestrian bridges and overpasses would have to be removed or rebuilt; overhead wires, lamp posts, road signs and traffic cameras would also have to be moved higher.

Vehicles which run underneath the bus would find it hard to change direction or lanes. Drivers may not see road signs clearly, and may be stressed or frustrated by the behemoth, say experts.

And if the TEB needed to make a U-turn, then that means all other vehicles would have to stop and make way for it.

Other safety concerns also sparked heated discussion.

TEB is overweight for current roads as it would reportedly weigh over 100 tonnes when full-loaded with 1,200 passengers.

And it is impossible for TEB to make a turn with its long carriage. Almost no current road junctions are vast enough for it to turn around safely.

The power supply system of TEB is designed to be installed on two edges of its carriage other than in the middle as what is applicable on the tramcars, which can't guarantee its safety and stability.

More terrifyingly, it's hard for passengers to escape from its elevated carriage in case of fire and other accidents.

Apart from the technical issues, the entity which runs TEB Tech has come under criticism.

TEB Tech shares a chairman with a P2P asset management company Huayingkailai, a subordinate of the Huaying Group, whose Nanjing branch was reportedly involved in illegal fund-raising last year.

A group spokesman has rejected the charge.