The 183-A Turnpike is an 11.6-mile north-south toll highway through Cedar Park and Leander in Williamson County northwest of Austin, Texas. It was constructed as a four-lane facility with the ability to expand to six lanes. It connects to SH 45 North and existing U.S. 183 at its southern end and extends north to Whitestone Boulevard.
183-A was developed by the state's first Regional Mobility Authority, Central Texas Regional Mobility Authority (CTRMA), which was legislatively authorized in 2001 to form at the county level to construct, operate, and maintain toll roads if a regional toll authority did not already exist. Their powers were expanded in 2003 to include the issuance of toll revenue bonds. To date, toll revenues have exceeded expectations.