U.S. Transportation Secretary Ray LaHood has announced that he will not serve a second term in President Barack Obama’s cabinet. The Illinois Republican was chosen by Obama to lead the transportation department following the 2008 election.

During his time as Transportation Secretary, LaHood oversaw the implementation of the Compliance, Safety, Accountability (CSA) program and also focused much effort on the issue of distracted driving in the U.S.

The DOT was also charged with distributing funding under American Recovery and Resource Act, one aspect of which as the $1.5 billion TIGER grant program which allowed the secretary to invest in critical projects that were difficult to fund through traditional programs.

DOT also worked with EPA on fuel efficiency for both commercial and passenger vehicles, resulting in the first-ever standards for heavy-duty commercial vehicles.

In a letter he sent to U.S. DOT employees this morning, LaHood thanked the employees for their efforts in the past four years and noted some of the accomplishments of the agency.

Here is the text of the letter:

“I have let President Obama know that I will not serve a second term as Secretary of the U.S. Department of Transportation. It has been an honor and a privilege to lead the Department, and I am grateful to President Obama for giving me such an extraordinary opportunity. I plan to stay on until my successor is confirmed to ensure a smooth transition for the Department and all the important work we still have to do.

 As I look back on the past four years, I am proud of what we have accomplished together in so many important areas. But what I am most proud of is the DOT team. You exemplify the best of public service, and I truly appreciate all that you have done to make America better, to make your communities better, and to make DOT better.

 We helped jumpstart the economy and put our fellow Americans back to work with $48 billion in transportation funding from the American Recovery and Investment Act of 2009, and awarded over $2.7 billion in TIGER grants to 130 transportation projects across the Nation. We have made unprecedented investments in our nation’s ports. And we have put aviation on a sounder footing with the FAA reauthorization, and secured funding in the Moving Ahead for Progress in the 21st Century Act to help States build and repair their roads, bridges and transit systems.

 And to further secure our future, we have taken transportation into the 21st century with CAFE Standards, NextGen, and our investments in passenger and High-Speed Rail. What’s more, we have provided the U.S. Merchant Marine Academy with the funding and leadership it needs to prepare a new generation of midshipmen to meet our country’s rapidly-evolving defense and maritime transportation needs.

 Closer to home, we also have made great strides. In December, the DOT was recognized as the most improved agency in the entire Federal government in the 2012 “Best Places to Work” rankings published by the Partnership of Public Service. Even more impressive, DOT was ranked 9th out of the 19 largest agencies in the government.

 Each of these remarkable accomplishments is a tribute your hard work, creativity, commitment to excellence, and most of all, your dedication to our country. DOT is fortunate to have such an extraordinary group of public servants. I look forward to continuing to work with all of you as the selection and confirmation process of the next transportation secretary moves forward. Now is not the time to let up - we still have a number of critical safety goals to accomplish and still more work to do on the implementation of MAP-21.  

 I’ve told President Obama, and I’ve told many of you, that this is the best job I’ve ever had. 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.

 Thank you, and God bless you.”