Two men were killed and three injured when a 40-tonne trailer truck overturned and flattened a car and a bike after hitting a taxi and a truck while speeding down the Kidderpore flyover around 10.30pm on Sunday.

The accident at the Fancy Market-end of the flyover highlights yet again how recklessly truckers drive at night, a witness said.

Cops can be seen taking money from truck drivers but they rarely book them for rash driving, he alleged.

A WagonR - weighing 975kg, nearly 1/40th of the container's weight - was a mangled mass of steel when six cranes managed to remove the truck, more than two-and-a-half hours after the accident.

By that time, Mohammed Sajid, 33, the driver who was trapped inside the car, was dead.

Muzammil Hossein, 24, who was riding pillion on the bike and who was trapped under the truck driver's cabin, was rescued by local people immediately after the accident. He was declared dead on arrival at SSKM Hospital.

Tahrim Asgar, 22, who was riding the bike, said he had seen the truck hurtling down the flyover after hitting two vehicles.

"When I realised the truck was about to overturn I tried to make a U-turn... but I could not ride any further. The truck fell, trapping one of my friends riding pillion. My left leg had come under the vehicle but I managed to free it in time leaving behind the bike," he said.

Asgar and his other friend Iftekhar Alam, 24, who, too, was riding pillion, and cabbie Krishna Nanda Upadhyay, 38, were discharged after first aid.

Police said the truck driver had lost control on the flyover and rammed into the railings on the left before hitting another truck on the right and a cab from behind.

The driver has been booked under sections 304A (causing death by rash or negligent act) and 279 (driving on a public way in a rash and negligent manner endangering human life) of the IPC. But he is yet to be arrested, the police said. All the vehicles have been seized.

In an almost similar accident in March 2014, 10 people were injured when a truck driver lost control of his vehicle, hit a car, crushed a taxi, knocked down two pedestrians before ramming into parked motorcycles on Andul Road in Howrah.

More than 50 per cent of accidents in the city take place between 10pm and 7am because of reckless driving by truckers, a police source said.

After 10pm, traffic sergeants are off duty, one-way rules are relaxed and trucks are allowed to ply on city roads.

The source said the number of road deaths in accidents involving heavy goods vehicles was "considerable".

Police records say 21 people lost their lives in road accidents on Diamond Harbour Road, 15 on Circular Garden Reach Road, 13 on Strand Road and seven on Basanti Highway - hundreds of trucks ply on these roads daily - in 2015.

The source claimed that rash and negligent driving by truckers were responsible for most of these deaths.

People who travel regularly at night say most goods vehicles are overloaded, they do not follow traffic signals and often travel at breakneck speed overtaking smaller vehicles.

"Trucks take sharp turns at breakneck speed and overtake small vehicles dangerously. The police can be seen stopping trucks to take money from the drivers but I have never seen any driver being booked for overloading the vehicle or jumping traffic signals," said Soumya Mukherjee, who often returns home past midnight from work.

V. Solomon Nesakumar, the deputy commissioner (traffic), denied allegations of police inaction.

He claimed that cops on the road take action against errant drivers whenever they are spotted.

"Such allegations are baseless. We book offending truck drivers whenever we find them breaking rules," he said.