“The Cup Series has seen a 72.7% increase in number of cautions for accidents and spins in races this season compared to last year through the first 15 events.”
nascar.nbcsports.com

Friday 5: Is more practice a path to reducing cautions in Cup races? - NBC
Brad Keselowski suggests it would be better for teams to have more practice on weekends to learn the nuances of the Next Gen car and reduce accidents.