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History
In the 1960s, Illinois' rapid population growth and the growing number of vehicles put significant strain on the state's transportation infrastructure. By 1960, Illinois became the fourth state to surpass 10 million people and between 1950 and 1960, the state saw a sharp rise in maintenance costs for roads. This rapid growth prompted a series of studies and investigations into how best to modernize Illinois' transportation system.
In 1963, the Illinois General Assembly created the Illinois Highway Study Commission to develop a comprehensive plan for the state’s highway system. The IHSC conducted public hearings and gathered input from government officials, industry leaders, and residents. Their reports, published in the mid-1960s, recommended a complete overhaul of the state's transportation system, including a more coordinated and efficient structure for managing roads, bridges and other transportation assets. The IHSC’s findings pointed to the need for a unified transportation department to replace the fragmented agencies handling transportation-related functions at the time.
By 1969, the second IHSC affirmed the need for a dedicated state transportation agency, inspired by similar agencies in other states and the U.S. Department of Transportation. The IHSC's third report in 1971 emphasized the importance of creating a cohesive and flexible department that could handle all forms of transportation, not just highways.
In February 1971, Gov. Richard Ogilvie, citing the central importance of transportation to the state's economy, called for the immediate creation of a state transportation department. He emphasized that Illinois’ economic prosperity was directly linked to its ability to efficiently move people and goods. A task force was formed to propose legislation, leading to the Transportation Bond Act of 1971, which authorized $900 million in bonds to improve the state's transportation network. This was later increased to nearly $1.2 billion.
On Jan. 1, 1972, Illinois officially created the Illinois Department of Transportation through the passage of Public Act 77-153, consolidating transportation responsibilities from various agencies into one department. Illinois became the 14th state to establish a dedicated transportation agency.
IDOT assumed the roles of the Department of Public Works and Buildings, the Office of Mass Transportation, and several other state agencies responsible for transportation oversight and safety. Although some functions, like tollways and motor vehicle services were initially excluded, IDOT's formation marked a new era in Illinois transportation, laying the groundwork for future growth and modernization.