In this March 3, 2017, file photo, Dale Earnhardt Jr. smiles in the garage during practice for the NASCAR Monster Energy Cup auto race at Atlanta Motor Speedway in Hampton, Ga. Hendrick Motorsports says Dale Earnhardt Jr. will retire at the end of this season. (AP Photo/John Amis, File)

NASCAR star Dale Earnhardt Jr. to retire

Dale Earnhardt Jr. abruptly announced his retirement at the end of the season Tuesday, a decision that will cost NASCAR its most popular dri…