Newer cars are generally safer than older cars, because "vehicle crashworthiness" has improved over time, and new cars are more likely to be equipped with modern safety devices.
The study authors note that graduated driver licensing laws - which began in Florida in 1996 and are now implemented across all states - have been "highly effective" at reducing the crash rates of teenage drivers.
However, rates of fatal crashes are about three times higher among teenage drivers than they are for adult drivers.
The authors say that as teenagers have an increased risk of loss-of-control crashes, using a safe vehicle is especially important among this age group.
Several factors contribute to the relative safety of any car. For instance, people in bigger, heavier vehicles are usually better protected than those in smaller, lighter vehicles.
Also, newer cars are generally safer than older cars, because "vehicle crashworthiness" has improved over time, and new cars are more likely to be equipped with modern safety devices such as side airbags and electronic stability control (ESC).
ESC has been found to reduce fatal single-vehicle crashes by about a half and fatal multiple-vehicle crashes by 20%.
Previous research has shown that teenagers often drive older or smaller vehicles. A national survey of parents of teenage drivers, conducted in May 2014, found that - despite parents generally rating vehicle safety as the most important factor to consider when buying their child a car - about a fifth of the teenagers were driving small cars and 60% were driving model year 2006 or older vehicles.
In the new study, the researchers analyzed data from the US Fatality Analysis Reporting System - which collects information on all vehicle collisions that result in a fatality within 30 days of the incident. The time period the study looked at was 2008-12.
Study compared cars driven by teenage and middle-aged drivers
The types, sizes and ages of cars driven by 2,420 drivers aged 15-17 years old was also compared with the cars driven by 18,975 drivers aged 35-50 years old.
The researchers found that, of the teen drivers in the study who died:
- 35% were driving a mid-size or larger car
- 29% were driving a mini or small car
- 17% were driving pickups
- 17% were driving sports utility vehicles (SUVs).
However, although about 1 in 3 fatally injured teen drivers died in a mid-size or larger car, the study found that teen drivers were significantly more likely than middle-aged drivers to be fatally injured in a smaller car - 29% of the fatally injured teenagers died in a small car, compared with 20% of fatally injured middle-aged drivers.
Teenagers were also more likely than middle-aged drivers to die in a mid-size car (23% vs. 16%), but they were significantly less likely to have died while driving a large pickup (10% vs. 16%).
Vehicles that were at least 6 years old were involved in 82% of the teen driver fatalities. Also, 34% of the vehicles involved in teen fatalities were 6-10 years old, 31% were 11-15 years old and 17% were 16 or more years old.
The researchers calculate that fatally injured teens were almost twice as likely as middle-aged drivers to be driving a car that was 11-15 years old (20% vs. 12%).
Only 1 in 10 of the cars driven by fatally injured teens had ESC and only a third had standard or optional air bags.
The authors describe the take-home findings of their study:
"Teenage drivers killed in crashes generally are not driving safer types of vehicles in terms of size and availability of safety features.
The superior safety profile of vehicles driven by fatally injured middle-aged drivers suggests room for improvement in the vehicles driven by teenagers."