Russell Hodge of Corning admitted to unintentionally causing the death of Cal Trans worker Gary Smith back on Nov. 14, 2010.
Smith's co-workers and family were happy to see Hodge finally confess.
Hodge was driving his Ford F-250 with a blood alcohol content of .20. He hit Smith while he was going 60 miles per hour just north of Chico on Highway 99.
Smith was working on a road construction site diverting traffic when he was struck.
Hodge was charged with second degree murder as an alternative to gross vehicular manslaughter.
Under Thursday's plea deal, he'll be sentenced to 15 years to life in prison.
"We cannot tolerate the carnage caused by drinking drivers, particularly those who have prior convictions," said Butte County District Attorney Mike Ramsey.
Hodge will be sentenced on February 28, 2013.