Interstate 35 through San Antonio serves as one of the main arteries for commuters, freight trucks moving goods throughout Texas, and tourists and vacationers.

To accommodate the growing demand on I-35, TxDOT has launched numerous projects, including various construction and planning improvements in the San Antonio area. Download a map showing these improvements and read more about them below.


  • Construction will begin soon on I-35 from I-410 south to I-410 north. This project will expand the mainlanes to eight lanes from six, change the current southbound I-35 to I-410 left exit to a right exit, and include other ramp improvements.

Environmental Study

  • TxDOT has begun an environmental assessment study on I-35 from I-410 south to FM 1103. This study is examining a potential project to construct additional mainlanes and make intersection improvements at major interchanges. 

Preliminary Planning Studies

  • Two preliminary planning studies, called Planning and Environmental Linkage (or PEL) studies, are looking at alternative routes and potential improvements for I-35. The I-35 Bypass PEL is focused on I-410, I-10 and Loop 1604 as alternatives to I-35. The I-35 Central PEL is studying I-35 between I-37 and US 90.

Updated Oct. 23, 2013