A 32-year-old Chinese man driving a BMW was told to move out of the centre lane by a traffic officer, but he refused.
When the light turned green, the driver in Shanghai just took off.
The officer, Mr Mao Shengquan, 32, grabbed the car's door frame but was thrown up in the air. He landed heavily with his police radio scattering all over the road, Hong Kong daily South China Morning Post reported.
He died later in hospital of his injuries. His wife is expecting their first child in a month.
The car driver stopped about 100m away and gave himself in.
"What do you mean? We are all in a rush, is this necessary?" he was recorded as saying on Mr Mao's police radio.
He told police later that he thought the officer was picking on him without realising that he had committed a traffic offence.
Mr Sun Jian, chief investigator of serious crimes unit, told the Shanghai Morning Post that the driver had been arrested for causing intentional injury.
"He made two serious mistakes," he was quoted by the newspaper as saying.
"First, turning left from a straight-moving lane. Second, he disobeyed a police order."
"The suspect did not realise he had violated a traffic regulation. He thought he had the right to turn left.
"He only admitted he stepped on the gas pedal too heavily."
Photographs and video of the incident have prompted an online discussion in China about the reckless driving on the country's roads and whether traffic police should be issued guns to give them more protection and power to stop offenders.
Drivers routinely ignore traffic regulations in China, including jumping traffic lights, driving through lines of pedestrians who have the green light to cross the road, parking in bicycle lanes and blocking emergency exits.
Some cities such as Shenzhen do allow traffic police to carry firearms, but Shanghai does not.
A study published in the medical journal The Lancet last year said more people were killed in traffic accidents in China than by cancer.
More than 87,000 people died on the country's roads in the first 10 months of last year, according to figures from the Ministry of Public Security
This article was first published on Mar 14, 2015.
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