NASHVILLE (AP) — Gov. Bill Haslam and Transportation Commissioner John Schroer have released the state's three-year, $1.5 billion transportation program.

The Haslam administration said the plan unveiled Thursday takes a conservative approach because of uncertainty over future federal transit funding. It contains no money to pay for early engineering work on new projects.

The spending plan includes $600 million to maintain, replace or repair roads and bridges around the state. It also envisions interstate projects, including truck climbing lanes, interchanges and capacity expansion on major routes.

The three-year program runs from 2015 to 2017.

About half of the state's transportation budget comes from the federal government, while most of the rest is generated from the state's tax on gasoline.