Howrah: An ambulance with a 78-year-old patient inside collided head-on with a taxi on Howrah bridge when the driver broke away from two lanes of traffic to enter the flank meant for vehicles moving in the opposite direction.

Joydeep Ghosh, a retired railway employee from Singur in Hooghly, was left screaming in pain after appearing to aggravate his hip injury when the ambulance driver failed in his attempt to repeat a risky manoeuvre he would have done many times.

Police said the cause of the accident, which occurred around 12.30pm, was a copycat move of ambulance drivers in Calcutta and the districts.

"Traffic on the bridge was not so high at the time that the driver needed to take such a risk. On nearing pillar number 21, he suddenly swerved and moved ahead to find the taxi in front," said an officer in the Howrah traffic guard.

"The taxi driver told us that the ambulance came at his car from a blind spot. It is difficult for any motorist in a Howrah-bound lane to immediately notice and avoid an approaching vehicle."

The patient was being shifted from the Eastern Railway Orthopaedic Hospital in Howrah to BR Singh Hospital in Sealdah when the collision occurred.

Officers of North Port police station and the Howrah Bridge traffic guard arranged a Karma ambulance - the acronym stands for Kolkata Accident Rescue and Medical Attention - to take Ghosh to Sealdah.

The ambulance driver got off the vehicle and fled before the cops arrived. "We have seized the ambulance (WB15A 5922) and are searching for the driver," said an officer at North Port police station.

A couple of months ago, a 72-year old patient being taken to a private hospital in south Calcutta fell off an ambulance stretcher and cut his forehead when the driver braked hard.

In a city beset with chaotic traffic, ambulance drivers are sometimes forced to take risks to save lives. But on most occasions, they are slaves to the habit of violating rules in the name of emergency service.

An officer in Lalbazar said traffic cops wouldn't usually prosecute an ambulance driver for breaking a rule while ferrying a patient. "The problem is that these drivers take risks even when there is no reason to do so."

The officer said the police had created green corridors for ambulances on many occasions so that critically ill patients or accident victims could reach hospitals faster.