PORTLAND, Maine (AP) — The executive director of the Maine Turnpike Authority has stepped down amid questions about turnpike finances and his leadership.

Paul Violette’s resignation was unanimously accepted Monday by the turnpike authority’s board. In a letter, Violette said he felt that his leadership had been called into question and was becoming a central issue for critics in the Legislature. He did not attend the meeting.

Violette’s future was called into question as the Legislature’s Government Oversight Committee continued to investigate the turnpike’s distribution of $157,000 in gift certificates to hotels and restaurants. Those gift certificates were distributed at Violette’s discretion.

Criticism of the turnpike authority’s handling of toll revenue has led to proposals to abolish the turnpike authority or divert more control of the toll road to the Legislature.