A new study has found that both - carrying passengers, and having a greater number of passengers in the car - is linked to an increased risk of a crash.
The study, by The George Institute for International Health, was intended to determine the danger of a crash related with passenger carriage compared with that of using a mobile phone while driving.
And the researchers found that passengers also contribute to road accidents, though not to the same extent as mobile phone use.
"Carrying passengers in the car has a number of potentially distracting effects that also occur with mobile phone use while driving. Moreover, carrying passengers may have additional effects on the driver, including peer influence,” study's lead investigator, Dr Suzanne McEvoy, says.
"Drivers with passengers were almost 60% more likely to have a motor vehicle crash resulting in hospital attendance, irrespective of their age group. The likelihood of a crash was more than doubled in the presence of two or more passengers," notes Dr McEvoy.
The study did find, however, that the danger of a crash is significantly lower in passenger-related factor, as compared to the mobile phone factor while driving.
"In contrast to mobile phone use, passengers, with some exceptions, are generally aware of the road conditions and can moderate their conversation as needed. However, although the risk associated with carrying passengers is lower than that associated with mobile phone use, it is likely to have a higher contribution to accidents because of the higher incidence of drivers taking passengers as opposed to using a mobile phone when driving," The George Institute's Professor Mark Stevenson, who also contributed to the study, said.
While the body of confirmation is growing in relation to the road safety risks connected with mobile phone use and passenger carriage, questions remain about how these factors impact on driving actions.
That each adds to driver disturbance and distraction is unquestionable, however, passenger carriage by young drivers may have added effects, as recent studies have indicated.
These studies propose that teenage passengers may amplify the risk of crash for young drivers by multiple pathways, which include not only driver distraction but also peer pressure.
"Further well-designed research is needed to investigate the factors underlying the increased risk for phone use and passenger carriage and the ways in which the risk can be reduced. Research of this kind can provide an excellent basis for examining road safety policy, with the opportunity to reduce both mobile phone-related and passenger-related crashes and injuries,” Dr McEvoy says.