SPRINGFIELD, Mo. (AP) — The Federal Highway Administration has approved a plan to extend Kansas Expressway south toward a southwest Missouri county.

The Springfield News-Leader reports the administration approved the project’s environmental assessment report. The approval allows Greene County to proceed with the design phase of the extension that would go down toward Christian County.

Opponents of the project say they’d rather see Greene County choose a different route for a north-south corridor because the expressway will create traffic congestion and road safety issues without easing the commute between counties.

County leaders say the corridor’s route has been set since the 1990s.

Timberbrook Property Owners Association members say attorneys they hired to challenge the environmental assessment are reviewing the administration’s decision.

Construction is expected to begin in summer 2018.