Washington, Jan 22 (IANS) Car designs may need to be reworked to protect the growing numbers of obese people who are more likely to die in crashes, according to a US study.

When Tom Rice of University of California at Berkeley, division of environmental sciences and his co-authors analysed the data from US Fatality Analysis Reporting System (FARS) for 1996 to 2008, they found obese drivers were more likely to die in severe collisions than normal weight drivers.

During this period, details of 57,491 road traffic collisions were submitted to the system. Researchers looked for collisions in which two passenger vehicles were involved, and for which the impact of the crash was the most harmful component of the incident, resulting in the deaths of one or both drivers, the British Medical Journal reports.

They also looked for collisions in which both parties had been driving vehicles of similar size and type. They selected 3,403 pairs of drivers for whom data on weight, age, seat belt use and airbag deployment were available, according to a California statement.

Almost half of these drivers (46 percent) were of normal weight, one in three was overweight and almost one in five (18 percent) were obese, according to a California statement.

Two thirds were male, and almost one in three was aged between 16 and 24; one in three was not using a seat belt properly - lap or shoulder only, rather than both - and in over half (53 percent) of cases, the airbag deployed.

The analysis showed that risk of death increased the more obese the driver was, according to the World Health Organisation classification, which categorises obesity from Levels I to III.

At Level I, obese drivers were 21 percent more likely to die; at level II they were 51 percent more likely to do so; and at level III they were 80 percent more likely to do so than drivers of normal weight.

When broken down by gender, obese women were at even greater risk. At level I they were 36 percent more likely to die; at level II they were more than twice as likely to do so; and at level III they were almost twice as likely to die.