Preliminary data collected by the National Safety Council (NSC) indicates deaths from motor vehicle crashes dropped 4% during the first half of 2014 to 16,180 compared to the 16,860 fatalities that occurred during the same six-month period in 2013.

While Deborah Hersman, NSC’s president and CEO, said in a statement that while definitive reasons behind this decrease are not know, studies show that 90% of crashes involve driver error, including speeding, alcohol use and distractions.

“Although it’s encouraging to see a decrease in fatalities, the unfortunate fact remains that many of these crashes could have been prevented,” she added.

In addition to human loss, motor vehicle crashes present a significant national cost in lost wages and productivity, medical expenses, administrative expenses, employer costs and property damage, according to NSC’s analysis, with the preliminary cost of motor vehicle deaths, injuries and property damage over the first six-months of 2014 totaling $123 billion.