Over 400 people may be killed and another 47,500 seriously injured in car crashes during the upcoming Thanksgiving Day holiday period, according to the National Safety Council (NSC).

Compared to last year, the fatality estimate is down nearly four percent, which is in line with an estimated drop in overall motor vehicle deaths in the United States.

Alcohol remains a persistent factor in fatal crashes and historical trends show that, on average, more than one-third of deaths during the Thanksgiving holiday period involve alcohol-impaired drivers.

The NSC is warning drivers to be particularly vigilant at the start of the holiday period, which runs from 6 p.m. Wednesday, Nov. 27, to 11:59 p.m. Sunday, Dec. 1. Drivers are urged not to drive under the influence of drugs, particularly as the decriminalization of cannabis continues in states throughout the U.S. and the widespread impact of the opioid crisis persists.

“Thanksgiving should be a time for family gatherings and good food, not the tragedy that a car crash can bring,” said Lorraine M. Martin, NSC President and CEO. “Let’s work to keep each other safe this holiday by planning ahead and avoiding impaired driving. Making smart decisions will help protect all of us as we travel for celebrations and other activities.”

The NSC is also reminding all vehicle passengers to buckle up no matter what seating position they are in. An estimated 165 lives may be saved this Thanksgiving holiday period if vehicle occupants wear safety belts, and an additional 97 lives could be saved if everyone were to wear safety belts, according to the NSC.