AUGUSTA — The Maine Turnpike Authority for years has been able to waste money and hide its expenses from public scrutiny while its board was “asleep at the switch,” sponsors of a bill to overhaul its administrative and financial procedures told a legislative committee Tuesday.

“The authority has become a kingdom of its own,” Sen. Roger Katz, R-Augusta, told the Transportation Committee during a hearing on a far-reaching bill that’s sponsored by 50 of Maine’s 186 lawmakers.

The legislation surfaces amid questions about lavish and unexplained expenses by toll road officials, which came to light through an audit by the Legislature’s Office of Program Evaluation and Government Accountability. It questioned the authority’s relationship with an engineering firm and its policies on travel and meal expenses.

The audit turned up $157,000 worth of gift certificates that were given out to charitable and trade groups between 2005 and 2007. Many of the recipients were not identified, and details of lavish travel expenses by former turnpike Executive Director Paul Violette remain clouded. Violette has resigned and the Legislature’s Government Oversight Committee, which Katz co-chairs, has referred the matter to the state attorney general’s office.

On another front, the Transportation Committee is seeking to restore public trust in the turnpike authority through the bill presented Tuesday.

“For years, the board of the authority was basically asleep at the switch,” Katz told the Transportation Committee. Senior management “failed the public by not speaking up on the excesses and potential criminal actions they saw around them,” he said.

Recommendations in the bill include transferring 5 percent of the turnpike’s operating revenues to the state Transportation Department, initiating a system of ongoing internal auditing of the authority’s books, and requiring that all purchases involve competitive bidding. The last recommendation seeks to prevent what lawmakers view as a no-bid relationship between the turnpike authority and an engineering firm.

The bill drew support from the state Transportation Department’s deputy commissioner, Bruce Van Note, who is also a turnpike authority ex-officio member. Van Note called it “a big step forward.”

John Dority, an authority board member, also supported the bill, saying the turnpike’s operations had long been built on trust. “The board is very interested in getting trust re-established,” Dority said.

Groups representing taxpayers and transportation advocates also spoke in support, and there was no opposition.

The chief sponsor, Republican Rep. Richard Cebra of Norway, said the bill was a collaborative effort of lawmakers, Gov. Paul LePage’s administration and even the turnpike authority, but added that it was still “a work in progress.”

He said the 5 percent revenue transfer provision was the most open to further debate and change. Other changes not in the bill are being proposed, notably reducing the current seven-year terms of board members to five years.

Rep. Donald Pilon, D-Saco, a member of the oversight committee who supports the shorter terms, said the longer period breeds “an old-boy network.”

The committee is to begin refining the bill Thursday.