The 12-lane project involves Hwys. 290 and 71 near the Y at Oak Hill.

The Oak Hill Parkway project —an effort to improve mobility near the intersection of Hwy. 290 and Hwy. 71—received environmental clearance, according to a Dec. 21 news release.A six-year study concluded that Alternative A —a non-tolled 12-lane project—has "fewer social, economic and environmental impacts," than multiple other alternatives proposed for the Y at Oak Hill, according to the Final Environment Impact Statement released today.The study evaluated potential impacts along Hwy. 290 from MoPac to RM 1826, and along Hwy. 71 from Hwy. 290 to Silvermine Drive.The project, as proposed, has raised environmental concerns from residents including the degradation of Williamson Creek and Barton Springs and the endangerment of heritage trees.Many have also expressed concerns about the scale of the project.Cost estimates for the Oak Hill Parkway range from Texas Department of Transportation's $440 million projection to Capital Area Metropolitan Planning Organization's $545 million estimate . The earliest the project could break ground is 2020, with construction expected to last approximately four years.