Capital Express Project


TxDOT is currently working on 10 stand-alone projects between RM 1431 and SH 45SE, including:

The Capital Express project would add two express lanes* in each direction and address all remaining safety and mobility improvements proposed under the Mobility35 Program that were not already included in the above stand-alone projects.

Two alternatives are being considered, an express lane build alternative and a no-build alternative. The build alternative could include placing the express lanes under the mainlanes where right of way is limited, providing direct access between the express lanes and frontage road, removing the upper decks from Martin Luther King Boulevard to Airport Boulevard and lowering I-35 through downtown.

Need & Purpose
  • Improve safety and mobility for all users of I-35 while minimizing right of way, community and environmental impacts
  • Provide a reliable travel time for cars, buses, vanpools and emergency vehicles using the express lanes
Project Description
  • Add express lanes (two lanes in each direction)
  • Widen all intersections and replace bridges to improve bridge clearances and east/west mobility
  • Improve bicycle and pedestrian accommodations along I-35 frontage roads and at east/west crossings
  • Project development funded by TxDOT
  • Construction not funded
  • Finalized schematic and environmental documentation: anticipated fall 2019
  • Construction letting: anticipated 2020*
  • Construction start: anticipated 2021*

*Dates are contingent on funding.


*Express lanes being proposed could include managed lanes, such as High Occupancy Vehicle (HOV) lanes, but do not currently include tolled management control lanes.

Project Vicinity Map

Capital Express Project Vicinity Map


Public Information Officer

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

(512) 832-7000