I-35 at Parmer Lane


The project includes the construction of a diverging diamond intersection, which is an innovative intersection to alleviate an existing bottleneck at the intersection of FM 734 (Parmer Lane) and I-35. The project also includes operational improvements at the Lamar Boulevard and Parmer Lane intersection.

Need & Purpose
  • Improve safety and mobility, including:
    • Improve traffic flow due to a high volume of left-turn traffic
    • Accommodate turning movements onto and from Parmer Lane
    • Eliminate the need for left-turn bays and left-turn signal phases
    • Minimize the number of potential conflicts between through traffic and left-turn traffic
Project Description
  • Replace the traditional intersection with a diverging diamond intersection
  • Widen and extend northbound frontage road
  • Add a southbound intersection bypass lane and reconstruct the northbound intersection bypass lane
  • Reconstruct two entrance and exit ramps south of Parmer Lane
  • Construct right-turn lanes at the intersection of Lamar Boulevard and Parmer Lane
  • Construct dual left-turn lanes from Parmer Lane to Lamar Boulevard
  • Improve bicycle and pedestrian accommodations
  • Project development funded by TxDOT
  • Construction funded by the Capital Area Metropolitan Planning Organization and TxDOT
  • Construction cost estimate: $32.5 million
  • Finalize schematic and environmental documentation: anticipated early 2017
  • Begin Plans, Specifications and Estimates (PS&E): anticipated mid-2017
  • Complete PS&E: anticipated late 2018
  • Construction letting: anticipated mid-2019
  • Construction start: anticipated mid-2019
  • Construction completion: anticipated mid-2021

Project Vicinity Map


Public Information Officer

TxDOT Austin District
P.O. Box 15426
Austin, TX 78761-5426

(512) 832-7000