AUSTIN, Texas (AP) — The director of the Texas Department of Transportation has announced he'll step down at the end of the year.

Joe Weber made the announcement Tuesday. The former three-star Marine general was chosen only last year to run the agency.

According to a statement released by TxDOT, Weber in his announcement to the agency's 11,000 employees called his past 18 months "a true highlight in my life." The agency is primarily responsible for maintaining and expanding the 80,000-mile state highway system.

The 65-year-old didn't say in the statement why he was leaving the $299,000-a-year job.

Weber, a 1972 Texas A&M graduate, had served as Texas A&M University's vice president for student affairs before being selected in April 2014 to lead TxDOT.