Should restrictions on passengers apply to young drivers?

Australia and international research clearly demonstrates that young and multiple passengers are a significant crash risk factor for young drivers.  The greater the number of peer-aged passengers, the greater the risk of crashing, and the greater the risk of death.  For example, research from the United States demonstrates that carrying one peer passenger increases young drivers’ fatality risk by 50% compared to driving alone, whereas carrying three peer passengers increases fatality risk three-fold.

In Australia, where the age of passengers is not reliably recorded, studies of Provisional drivers have shown their odds of crash increase between 1.4 and 1.5 when carrying one passenger (of any age), and between 2.3 and 2.6 when carrying three or more passengers.

Prior to the introduction of passenger restrictions in Victoria, carrying more than one passenger increased first-year Provisional drivers’ fatal crash risk four times the level of driving alone or with only one passenger.  More than one-quarter of these drivers involved in fatal crashes were carrying multiple passengers at the time of crash.  The magnitude of this risk is even more apparent when considering that driving with passengers represents only 9% of young Victorians’ total on-road driving time.

The risk of death for a teenage passenger is also greater when a teenager is driving. In the United States, nearly three-quarters of all crash fatalities involving 15 year olds occur with teenage drivers.

Risk of crash is increased when:

• Passengers are of a similar age as the young driver, particularly male peers.
• There is more than one passenger of any age.

Risk of crash is reduced when:

• The passenger is an adult aged 25 or more.
• The passenger is a child aged 12 or under.

This is, however, a need to look at peer passenger influences in more detail as we know little about the mechanisms behind why risk increases so dramatically when passengers are present.  Distraction is likely the major reason. Peer passengers may also directly (verbally) encourage the young driver to take risks or indirectly (if the driver believes this is what the passengers want).

There is also developing evidence from the United States that the gender of the peer passenger may also be important. An observational study found that when a young male was the front seat passenger, the young driver was more prone to speeding and drove closer to the vehicle being followed moreso than other drivers on the road. When that passenger was a young female, the young driver maintained similar speeds and following distances as other drivers. These findings held whether the young driver was male or female.

Support for restrictions

Restricting similar-aged passengers as part of graduated licensing schemes has significantly reduced the number of crashes that cause death, both among young drivers and their passengers. For example, following the introduction of passenger restrictions in the United States, fatal crashes involving teenage passengers reduced by 41%, and crashes involving passengers of other ages reduced by 49%.  The number of fatal crashes involving 16-year olds carrying three or more passengers reduced by half.

In Australia, different states have introduced different requirements for carrying peer passengers for first-year Provisional drivers.

• In Victoria, no more than one passenger aged 16-21 can be carried at any time of day.
• In Queensland and New South Wales, no more than one passenger aged 21 and under can be carried between 11pm and 5am.
• In Western Australia, no more than one passenger can be carried between 12am and 5am for the first 6 months.
• Other passenger restrictions apply in several states when returning to driving after a licence suspension.

Research from New Zealand and the United States has clearly shown that strong passenger restrictions, that is restriction to none or only one passenger at all times – not more passengers and not just at night – is a feature of the most effective graduated licensing models.

Potential issues

Young drivers do not view peer-aged passengers as risky.  In a study in the United States, only 10% of teenagers thought that carrying peer passengers was hazardous (compared to 87% of teenagers believing drink driving was hazardous).  These views may lead to less compliance with peer passenger restrictions.

There is concern that passenger restrictions affect “designated driver” strategies (also known as “captain” or “sober Bob” schemes), where one driver remains sober to transport others who have been drinking alcohol.  Such strategies can be effective for adults, but they are not recommended for young drivers.  A young driver does not have enough experience to manage additional peer passengers, especially when those passengers may be under the influence of alcohol or other drugs.  Unfortunately, research has also shown that young designated drivers often consume alcohol and make inaccurate judgements when trying to calculate number of drinks by consumption time to determine if they have sobered up enough to drive.  Sometimes, the “designated driver” is actually the person least drunk, rather than a completely sober driver.  Therefore, it is recommended that the “designated driver” strategy be discouraged among young people and alternative strategies be identified instead, such as public transport or a reliable adult driver.

The focus of passenger restrictions is reducing the high-risk social recreational driving common when young people drive and ride together.  Therefore exemptions to the restriction should be allowed for “purposeful driving” such as for study, work, medical, religious and family activities – and without the need for prior registration of these.  Pre-registration can pose difficulties for licensing authorities, police and young drivers in rural and remote communities where access to registration offices can be limited.  There is also no research yet to indicate whether this would be more effective than just requiring the young driver to show proof of trip purpose at the time of the trip. 

Such exemptions allow parents of young children and infants to be carried (despite restrictions in some state for all passengers aged 21 or under) – as drivers of young children and infants are likely to be driving for family or work (e.g. babysitting) purposes.  This would also allow young drivers to transport their siblings.  While there is increased risk of crash for young drivers carrying peer-aged siblings compared to adult drivers, research suggests this risk is lower than for young drivers carrying non-sibling peers.  Nonetheless, it would not be recommended very soon after Provisional licensure or for social recreational driving.

It is also important to note that there should be no passenger restriction during the Learner phase of licensing.  Even though there are reports of increased odds of crash for Learner drivers who carry multiple passengers (especially 16 and 17 year olds), it is important that Learner drivers practice under these conditions when appropriately supervised and when crash risk is at its lowest.  However, it is recommended that the Learner driver does not carry passengers until they are competent in the manual handling of the vehicle and have many hours of driving practice with just a supervisor and no other passengers.

Factbase recommendations

Passenger restrictions are effective and should restrict first-year Provisional drivers to one peer passenger at all times, with administrative exceptions.

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