State House Vice Speaker Jon Riki Karamatsu said he made a serious error in judgment that led to his arrest early yesterday on suspicion of drunken driving.

Police said Karamatsu, 32, was traveling west-bound on Moanalua Freeway at about 1:15 a.m. when he lost control of his car and struck a concrete pillar at the Ahua Street overpass.

Karamatsu, D-41st (Waipahu, Village Park, Waikele), failed a field sobriety test and was taken to the Kalihi police substation, where a Breathalyzer measured his blood-alcohol content at 0.171 — more than twice the .08 blood-alcohol level above which a person is deemed to be under the influence, police said.

Bail was set at $500.

Karamatsu, in a statement, said he had been out socializing with friends.

"I made a serious error in judgment," Karamatsu said in the statement. "I want to apologize to my family, my colleagues and constituents for any trouble or embarrassment caused by this incident. I will cooperate fully with the court on this issue. I do understand that elected officials should be held to a higher standard, and I will work very hard to regain the public's trust."

State House Speaker Calvin Say, D-20th (St. Louis Heights, Palolo Valley, Wilhelmina Rise), said he would speak with Karamatsu and other House Democrats about the incident.

Say has the option of appointing a committee of lawmakers to review the incident and suggest whether any punishment is necessary.

"I was very disappointed because I truly believe that we take drunk driving very seriously," Say said. "This particular incident reflects that it was very poor judgment on Jon Riki's part."

Say described Karamatsu as a "tremendous legislator."

"He is truly a young man that will have great potential," Say said.

Karamatsu, an attorney and small-business owner, was first elected in 2002. He was chosen by Say as vice speaker before last session after a leadership shuffle, in part to have a younger lawmaker on the leadership team.

Court records show Karamatsu paid a fine of $137 in January after being cited Jan. 19 for driving 51 mph in a 35-mph zone.