Transportation Secretary Ray LaHood is stepping down from his post, according to an administration official.
LaHood, one of two Republicans in President Obama's first-term Cabinet, will stay on in his position until a successor is confirmed.
LaHood added that the achievements of the Transportation Department while he served as secretary "are significant," noting that the department made strides in improving safety for transit systems, highways and pipelines.
"I’ve told President Obama, and I’ve told many of you, that this is the best job I’ve ever had," LaHood said. "I’m grateful to have the opportunity to work with all of you and I’m confident that DOT will continue to achieve great things in the future."
LaHood is a former Republican congressman from Illinois. He and former Secretary of Defense Robert Gates were the only Republicans to serve in Obama's first Cabinet. Obama has nominated former GOP Sen. Chuck HagelChuck HagelSenators tear into Marines on nude photo scandal Lobbying World Who will temper Trump after he takes office? MORE (Neb.) as Defense secretary for his second term.
LaHood told The Associated Press that he does not plan to run for office in Illinois again. He said "you should go out while they're applauding."
In a statement, the president praised LaHood's tenure at the Department of Transportation, saying "every American who travels by air, rail or highway can thank Ray for his commitment to making our entire transportation system safer and stronger."
"I also want to thank Ray for his friendship. Years ago, we were drawn together by a shared belief that those of us in public service owe an allegiance not to party or faction, but to the people we were elected to represent," Obama added. "And Ray has never wavered in that belief. As secretary of Transportation, he has fought to create jobs and grow our economy by rebuilding our roads, bridges and transit systems."
LaHood's tenure at the transportation department saw contentious fights with Congress over funding for road and transit projects and over the Federal Aviation Administration (FAA). During LaHood's four years, lawmakers passed a $105 billion surface-transportation bill and a $63 billion FAA reauthorization bill, ending standoffs over both appropriations measures that predated the former congressman's arrival to the DOT post.
The FAA funding measure came after a memorable shutdown of the agency in 2011 that saw LaHood and Obama criticize Congress for putting thousands of aviation employees out of work for nearly two weeks.
LaHood and Obama stressed at the time that the FAA shutdown did not affect the safety of air travelers, but the impasse cost the federal government an estimated $30 million per day because the FAA could not collect taxes on airline ticket purchases without congressional authorization.
LaHood also targeted airlines' treatment of their customers during his tenure, enacting a "Passengers Bill of Rights" that imposed fines for excessive delays, inadequate fee notifications and lost luggage. Under the rules, airlines faced fines of up to $27,500 for each passenger who is stranded on a plane for more than three hours.
Airlines were also required to refund baggage fees paid by their customers if their luggage was lost.
More recently, LaHood has been embroiled in the FAA's decision to ground the Boeing 787 "Dreamliner" airplane after a series of battery defects, including one that sparked an electrical fire. LaHood came under fire for declaring the 787 was "safe" to fly only days before the FAA decided to take the planes out of flight.
In a speech to the Washington Aero Club that will likely serve as his final public remarks as Transportation secretary, LaHood defended his comments about the safety of the 787.
"On the day we announced the planes were safe, they were," LaHood told reporters after making his remarks. "On the day that we announced that there was another incident and we were grounding the planes, we felt this was the time to ground the planes."
During the speech LaHood told aviation industry officials that "together, we have accomplished a lot over the last four years.”
"One of the most far-reaching accomplishments was FAA reauthorization," he said. "We put an end to four-and-half years of stop-gap extensions. We provided stability for industry and we gave the FAA the resources to continue to move forward with NextGen."
The Transportation Department under LaHood also rolled out two waves of joint auto mileage and greenhouse gas rules with the Environmental Protection Agency that won praise from climate and energy security advocates.
The rules will require automakers to achieve a fleetwide average of 54.5 miles per gallon for cars and light trucks by 2025. The standards will raise the price of new vehicles, but ultimately save consumers over $1.7 trillion at the gas pump and curb U.S. oil consumption by 12 billion barrels, according to administration estimates.
LaHood also pushed a no-texting-while-driving campaign at his department.
He frequently cited the fact that the number of states with legislative bans on texting behind-the-wheel went from single-digits to more than 30 during his tenure at DOT. LaHood was fond of waving his own cellphone in speeches and warning audiences that they should put theirs away when they were driving.
—Ben Geman contributed to this story.
This story was last updated at 11:20 a.m.