Interstate 35 in Texas

Interstate 35 in Texas is a major north–south Interstate corridor linking the United States–Mexico border at Laredo to the Red River near Gainesville, forming the backbone of the Texas Triangle megaregion between San Antonio, Austin, and Dallas. The highway serves as a primary freight route connecting ports and maquiladoras to inland markets and intersects numerous historic corridors, including segments of U.S. Route 81 and U.S. Route 83. I-35 is split into two signed branches— I-35E through DFW and I-35W through the Fort Worth side—before rejoining north of the metro area.

Route description

I-35 enters Texas from Nuevo Laredo at Laredo, where it intersects international trade facilities near the World Trade Bridge. From there the route parallels U.S. Route 83 and passes through the Rio Grande Valley agricultural hinterland, skirting Eagle Pass freight arteries and connecting to Uvalde and Kerrville before descending into the San Antonio urban area. In San Antonio the highway forms part of the Loop 1604 and overlaps with segments of I-10 and I-37 near the Alamo and San Antonio River Walk. Proceeding northeast, I-35 approaches the Austin central business district, where it passes near University of Texas and Capitol grounds and links to U.S. Route 290 and SH 45. North of Austin, I-35 bisects the Round Rock and Georgetown suburbs, serving high-tech campuses such as those of Dell Technologies and providing commuter access to Williamson County. Approaching the Dallas–Fort Worth metroplex, the route splits into I-35E through Dallas—passing near DFW Airport periphery connections—and I-35W through Fort Worth; the branches reconnect before continuing north past Denton and terminating near the Red River.

History

The corridor that became I-35 followed long-established pathways used by Spanish Empire explorers and later by the Chisholm Trail and U.S. Route 81. Planning during the mid-20th century tied I-35 to the national Federal-Aid Highway Act of 1956, and construction in Texas proceeded in phases through the 1950s–1970s, with notable early completions near Laredo and the DFW. Urban sections, especially through San Antonio and Austin, generated controversy tied to community displacement and downtown routing decisions that involved civic leaders, neighborhood groups, and state agencies such as the Texas Department of Transportation. In the late 20th century, population growth across the Texas Triangle prompted major widening and interchange projects, including expansions at the MoPac Expressway convergence near Austin and reconstruction near Kendall County. The designation of I-35E and I-35W dates to policies accommodating the DFW split, reflecting historical trade and rail alignments through Fort Worth and Dallas. I-35 has been the focus of litigation and environmental review involving agencies such as the Environmental Protection Agency and advocacy by organizations including local metropolitan planning organizations.

Exit list

Major interchanges along I-35 connect to numerous principal routes and facilities: in Laredo the highway links to US 59 and access to the International Bridge crossings; in San Antonio it intersects I-10, I-37, and US 281 near downtown; in Austin it meets US 290, SH 71, and frontage-road systems serving the South by Southwest activity and Austin–Bergstrom International Airport; northward, junctions provide access to SH 130 and SH 45; within the Dallas–Fort Worth metroplex the split provides connections to I-635, I-20, I-30, and SH 114 near DFW Airport and downtown cores. The corridor’s exit numbering and mileposts follow Texas Department of Transportation conventions and reflect auxiliary business routes and frontage-road interchanges in urbanized counties like Travis County and Bexar County.

Future and planned improvements

Planned projects aim to address congestion and freight demand across the corridor. In the Austin area, reconstruction projects coordinated with Capital Metropolitan Transportation Authority initiatives and Project Connect planning include managed lanes and multimodal integration near UT Austin and Capitol zones. The North Central Texas Council of Governments and the Metropolitan Planning Organization for San Antonio have proposed interchange upgrades and managed lanes to improve throughput near Dallas and San Antonio. Freight-focused improvements near Laredo coordinate with port authorities and customs infrastructure to streamline trade flows involving maquiladoras and logistics firms. Environmental reviews and funding proposals have involved federal agencies such as the Federal Highway Administration and state bond measures, while community engagement includes neighborhood coalitions and business associations in Austin, San Antonio, and Dallas–Fort Worth.

Auxiliary routes and business loops

I-35 in Texas includes numerous auxiliary designations and business loops that preserve historic alignments and provide downtown access. Notable auxiliary routes include I-35E through Dallas and I-35W through Fort Worth, along with business loops through New Braunfels, Waco, and Temple. These business routes follow earlier U.S. Route 81 and state highway corridors, connecting municipal downtowns, regional universities such as Texas State University and Baylor University, and industrial parks. Several spur and loop designations intersect with state highways such as SH 46 and SH 45, facilitating local circulation and redevelopment initiatives along former mainline alignments.

Category:Interstate Highways in Texas