The study by the Transport Research and Injury Prevention Programme (TRIPP) says in 2001, Bluelines were involved in 3.3 per cent of fatal accidents; it has now gone up to 7 per cent.

The study also says that in nearly 38 per cent of cases, the offending vehicle is not known: Delhi Police has not been been able to identify those vehicles which killed 794 persons in 2006. In 2001, it was 32 per cent.

“The data for last five years shows that in a majority of the cases, the accused vehicle is unknown. What is more dangerous is that there has been an increase of at least 6-7 percent over the years,” said Geetam Tiwari of TRIPP.

Traffic experts say this trend is scary for policy planners as the “problem area” still remains to be identified. “It indicates that our enforcement measures are sloppy, apart from poor policing,” said Tiwari.

A major chunk of these hit-and-run accidents could have been caused by trucks and other heavy vehicles, which mostly ply at night, they said.

A survey on why the share of accidents caused by Bluelines has gone up as compared to other heavy vehicles showed that the drivers are paid Rs 2.30 per kilometer, after working for 12-16 hours each day.

The survey was carried out on five south Delhi bus routes: 442, 306, 34, 764 and 427.

The study also notes that the location of bus stops as a major cause for accidents. “Location of bus stops is usually far away from intersection, which forces people to get down as close to the intersection,” the study observed.