The Senate unanimously passed a bill toughening laws for drunken driving Thursday in the final floor session of the year.

The bill is aimed toward increasing penalties for arrests involving operating a vehicle while intoxicated in Wisconsin, a state that has the highest rate of drunken driving in the nation, according to the Department of Transportation.

The bill would strengthen current legislation by making fourth-offense OWIs a felony if committed within five years of a previous offense and criminalize a first offense if a child under the age of 16 is a passenger in the vehicle.

It would also require ignition interlock devices for all repeat offenders and first-time offenders with blood alcohol content of .15 or higher.

A similar OWI reform bill was passed by the Assembly in September, but currently resides in the Senate Committee on Judiciary, Corrections, Insurance, Campaign Finance Reform and Housing.

According to a statement released Thursday by Assembly Speaker Mike Sheridan, D-Janesville, the Assembly is willing to call an extraordinary session in order to review the bill and hopefully pass it in a timely manner.

“This issue is too important to let the calendar dictate the timetable. We feel it’s critical to include treatment options and a stable funding source,” Sheridan said. “We will sit down with the Senate in the coming days and work out the minor differences.”

Sen. Jim Sullivan, D-Wauwatosa, authored the bill and began the debate by reading a letter written by Matthew Heroux, the sibling of an 18-year-old victim of drunken driving, according to a statement released Thursday by Sullivan.

“It is frustrating to realize there is nothing within the power of the legislative body to make up for the kind of tragedy families have suffered as a result of drunk driving. We cannot bring Talhia home for the holidays, but we can honor her memory by passing [this bill],” Sullivan said.

Senate Democrats previously proposed an increase on the state’s existing liquor tax to help pay for the bill, but this amendment was deemed no longer necessary and was removed from the bill.

Many around Wisconsin thought this was progress in the fight against drunken driving, even across party lines. Kimber Liedl, spokesperson for Sen. Scott Fitzgerald, R-Juneau, said the legislation passed today will help make the state a less dangerous place for both motorists and others.

“Scott feels it is a step in the right direction in tightening drunk driving penalties and preventing the repeat offenders that we’ve been reading so much about in the papers, and making the roads safer,” Liedl said.

Frank Harris, spokesperson for the Wisconsin Mothers Against Drunk Driving, said the bill is a good first step towards necessary reforms, but there is still further work needed.

“This is really a first step toward further reform that will save lives in Wisconsin. Only in Wisconsin does [this bill] represent progress against the fight against drunk driving,” Harris said.

The Senate also passed bills Thursday concerning public financing for Supreme Court election and education reforms that would make the state eligible for the federal grant program Race to the Top, which President Barack Obama spoke about at Wright Middle School Wednesday. The Race to the Top bill is now free to be considered by the Assembly.

— Alicia Yager contributed to this article.