Gov. Brian Kemp’s top transportation official will gain more responsibilities, leading three agencies that oversee transit planning, toll roads and other services in metro Atlanta.

Jannine Miller, currently the governor’s planning director at the Georgia Department of Transportation, will become the next director of the State Road and Tollway Authority, the agency announced Wednesday. The agency operates the region’s growing network of toll lanes.

Two other agencies are expected to name Miller their director on Thursday: the Atlanta-Region Transit Link Authority, or ATL, which oversees transit planning and funding in a 13-county region, as well as the state’s Xpress bus service, and the Georgia Regional Transportation Agency, which addresses regional transportation and air quality issues.

Miller will keep her duties as GDOT planning director, which allows her to set priorities for transportation funding across the state. In that position, she is already one of the most powerful transportation officials in Georgia. Adding the other three agencies to her portfolio will increase her authority.

Kemp appointed Miller director of the SRTA last month, and the SRTA board confirmed her appointment Wednesday. Kemp has also recommended Miller to serve as executive director of the GRTA and the ATL board.

In announcing her appointment to the SRTA, Kemp called Miller “a leader in the field of transportation and infrastructure on both the state and national levels.”

“Jannine will bring an innovative approach and a deep knowledge of the issues facing commuters and those who move Georgia-made products through and beyond Georgia as she steps into these new roles,” he said.

Miller will replace Chris Tomlinson as director of the ATL board, the SRTA and the GRTA. Tomlinson left the posts in the spring to work in the private sector.

Miller has a long record of transportation leadership. She has served as GDOT planning director for the past three years. She oversees long- and short-term planning, including strategies for investing billions of dollars of state and federal transportation funds.

Before she came to GDOT, she was a senior adviser to U.S. Transportation Secretary Elaine Chao in the Trump administration.

Miller also has served as director of the Center of Innovation for Logistics at the Georgia Department of Economic Development, as executive director of the GRTA and as a senior planner at the Atlanta Regional Commission. In the private sector, she was senior manager of supply-chain finance at Home Depot.