Dipping gas prices, an improving economy and more vacation travelers hitting America's highways could add up to one of the deadliest summers for drivers, safety advocates warn.
It's a period they're calling "100 deadly days."
The concern follows an 8 percent increase in monthly motor-vehicle deaths over the latest six-month period compared to the same time the previous year, according to a new study from the nonprofit National Safety Council.
That amounts to 17,820 fatalities from October 2014 through March 2015, up from 16,531 deaths during the corresponding six months of 2013-14.
States with some of the biggest increases include Arkansas, Nevada, Oregon and Utah, the study found.
With travel more affordable — combined with the typical increase in speeding- and alcohol-related crashes during the summer months — the roads could prove more perilous than usual.
"Unfortunately, after decades of decline when it comes to highway fatalities ... we have seen an uptick on the fatalities numbers on our highways," National Safety Council President Debbie Hersman told NBC News. "This is not an anomaly and we're really concerned because we're heading into the deadliest days of the year: the summertime."
The latest fatality numbers come a week after the nonprofit group found that 27 percent of all roadway crashes are caused by distracted driving. Cellphones are a major culprit in crashes: The report found that using one while driving makes an auto accident four times more likely.
"It's not just phone calls or texts — it's everything that we can do on those devices that have really become a part of our lives and make it very hard for us to separate from them," Hersman said. "But when you're behind the wheel isn't the time to be updating your Facebook page, checking your messages or even making dinner reservations."
Dr. Peter Shearer, medical director at the Mt. Sinai Emergency Department, said summer guarantees a rise in patients rushed to the hospital for automobile accidents. They suffer from fractured bones and severe head trauma — if they survive at all, he said.
"More people driving cars are going to lead to more injuries," Shearer said. "Add in a dangerous mix of ... alcohol and some degree of distracted driving, (it) just compounds it to make it worse."
He added that the long road trips synonymous with summer travel also have an effect.
Families are "driving longer periods of time on the road, so there is probably some degree of sleep-related death, sleep deprivation and people dozing at the wheel," Shearer said.
The National Safety Council has several tips on its website for lessening the risks associated with driving:
- Avoid using a cellphone, even a hands-free device
- Wear a seat belt, including the passengers in the back seats
- Appoint a designated driver who is not consuming alcohol or using drugs
- Take breaks during long road trips and get adequate rest