Preliminary data collected by the National Safety Council indicates deaths from motor vehicle crashes during the first six months of 2014 are down 4%, compared to the same six month period last year, according to newly released figures.

In 2014, 16,180 traffic deaths occurred from January through June, compared to 16,860 in 2013.

Definitive reasons behind the decrease are not known, said the group

“Studies show that 90% of crashes involve driver error, including speeding, alcohol use and distractions,” said Deborah Hersman, president and CEO at NSC. “Although it’s encouraging to see a decrease in fatalities, the unfortunate fact remains that many of these crashes could have been prevented.”

In addition to human loss, NSC said motor vehicle crashes present a significant national cost in lost wages and productivity, medical expenses, administrative expenses, employer costs and property damage. The preliminary cost of motor vehicle deaths, injuries and property damage through June was $123 billion. 

The January through June figure for 2014 for highway fatalities was down 9% from the same period in 2012. The 6-month total for 2013 was 16,860, a 5% decrease from 2012. The 2012 figure was 8% higher than 2011.

The estimated annual death rate is 10.8 deaths per 100,000 population, down 3% from the preliminary 2013 rate of 11.1. The estimated annual mileage death rate is 1.2 deaths per 100 million vehicle miles traveled, unchanged from the preliminary 2013 rate.

Medically consulted motor-vehicle injuries for the first six months of 2014 are estimated to be about 1.7 million, a decrease of 3% from 2013. Medically consulted injuries are not comparable to previous disabling injury estimates, according to NSC

The National Safety Council is a nonprofit organization whose mission is to save lives by preventing injuries and deaths at work, in homes and communities, and on the road, through research, education and advocacy.