In 2015, Caltrans released a new mission statement: "Provide a safe, sustainable, integrated and efficient transportation system to enhance California's economy and livability.

"[6] The earliest predecessor of Caltrans was the Bureau of Highways, which was created by the California Legislature and signed into law by Governor James Budd in 1895.

[7] On August 7, 1912, the department broke ground on its first construction project, the section of El Camino Real between South San Francisco and Burlingame, which later became part of California State Route 82.

[9] The year 1912 also saw the founding of the Transportation Laboratory and the creation of seven administrative divisions, which are the predecessors of the 12 district offices in use as of 2018[update].

[11] To help manage all the additional work created by this massive expansion, an eleventh district office was founded that year in San Diego.

[11] The enactment of the Collier–Burns Highway Act of 1947 after "a lengthy and bitter legislative battle" was a watershed moment in Caltrans history.

[17] In 1970, the enactment of the National Environmental Policy Act and the California Environmental Quality Act forced Caltrans to devote significant time, money, people, and other resources to confronting issues such as "air and water quality, hazardous waste, archaeology, historic preservation, and noise abatement.

[18] During the 1980s and 1990s, Caltrans concentrated on "the upgrading, rehabilitation, and maintenance of the existing system," plus occasional gap closure and realignment projects.