Brennon Morioka is stepping down as the state transportation director to return to the private sector.

Morioka, who has worked at the state Department of Transportation since 2005, has accepted a position as executive vice president of Shioi Construction Inc.

Michael Formby, deputy transportation director and head of the agency’s Harbors Division, will take over as acting director.

Morioka is the third transportation director under Gov. Linda Lingle, after Barry Fukunaga, who became her chief of staff, and Rod Haraga.

Morioka began as deputy director of the state Highways Division. During his tenure, the state began a number of highway projects on Oahu, including opening Kualakai Parkway, widening Fort Weaver Road and construction of the Kapolei interchange.

On Maui, Haleakala Highway and Mokulele Highway projects were completed, and on the Big Island, the first phase of the Queen Kaahumanu Highway was finished.

He also began large-scale modernization plans for state airports and harbors, work that is still continuing.

"I’d like to think that we’ve been able to spread some of the benefits across the entire state," Morioka said yesterday.

Morioka said he is most proud of the reduction in traffic fatalities for Hawaii. In 2005, when he began state work, Hawaii had 140 fatalities. Last year, Hawaii had 109 fatalities.

"Once we started doing the strategic highway safety plan, we saw our fatality numbers drop," he said. "I think saving lives has been one of the biggest issues we’ve been fighting."

It’s likely that Formby will head the agency until the end of Lingle’s term, Morioka said.

"Brennon has been a visionary leader who has always focused on improving government efficiency and ultimately enhancing the quality of life for all the people of Hawaii," Lingle said.

Morioka worked as an engineer in the private sector before he began state service, and he has a doctorate in civil engineering from the University of Hawaii at Manoa.

Shioi Construction is a firm in Pearl City. The company has been a building contractor for the state Department of Hawaiian Home Lands, according to the state Procurement Office.

Formby is a lawyer by training. He is the former chairman of the Land Use Commission, and the current chairman of the state Employer-Union Health Benefits Trust Fund.