An apparent road-rage incident in which a restaurant manager was crushed and killed after accidentally scraping a car in a crowded carpark at an upmarket shopping centre in the centre of Delhi has provoked unusual introspection among the city's 15 million inhabitants.

In a city where queuing is an alien concept, traffic laws are systematically flouted and, apparently, the smallest disagreement can lead to murderous violence, questions are being asked.

According to police statistics reported in the Hindustan Times, 78 people died last year in Delhi "due to sudden provocation over trivial issues". In five years, 382 murders were committed by "people who let their anger explode".

Last week a 21-year-old was stabbed to death after refusing to lend customers at his mobile phone shop a screwdriver.

Many of the deaths however occur on the roads or involve cars: a man was beaten to death after upsetting his killer's plate of takeaway chicken tikka when he opened his car door; another was stabbed to death after scraping a car; a petrol pump attendant was run over and killed in a dispute over correct change.

Last month a 24-year-old deliveryman died after being assaulted by the owner of a car he accidentally scraped. "It was a small scratch. For this he lost his life," his widow told reporters.

According to OP Mandal, the officer investigating the attack, such incidents are becoming more common. "This is what we are seeing every day. A minor quarrel escalates, people take the law into their hands, and a life is snuffed out."

Headlines in the local media asked: "What makes Delhi-ites so short fused?" Roughly 10m cars, buses, trucks, scooters and motorbikes crowd the city's potholed roads every day, at least twice as many as 20 years ago. Driving in the city is a chaotic free-for-all where right of passage is determined by aggression and the size and value of a vehicle. Driving in lane is considered odd, the use of horns is compulsive, and tailgating systematic.

"In our country there is no respect for law. Physical encounters are considered macho," said Satyendra Garg, the police official in charge of New Delhi traffic.

Sociologists attribute the violence to broader changes. India's capital was once a quiet government town, but it has become an overcrowded and hectic metropolis. Limited resources encourage cut-throat competition and insecurity.

"People are changing with it. They are increasingly finding it hard to control any kind of emotion," said Rajat Mitra, director of Swanchetan, an NGO supporting survivors of violence, abuse and trauma.

Compounding the problem is a generalised disrespect for a poorly trained and often corrupt police force whose fining powers have not kept up with the earning power of India's elite. Police officers fear the summer, when temperatures of more than 50°C mean tempers fraying even faster.