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I-35 San Antonio Area Freeway System
Interstate 35 South (South PanAm Freeway)

This page last updated May 10, 2019

I-35 South highlight map This page covers Interstate 35 west and south of downtown San Antonio from the I-10 West interchange to Loop 1604. For information on I-35 north of downtown, see the I-35 North page.

Length: 16 miles


On this page

Schematic Lanes Access
Special features
& notes
Traffic Media


With the passage of NAFTA and the boom of the Eagle Ford Shale oilfield south of San Antonio, I-35 South has become an increasingly important spoke in San Antonio's freeway system. This segment serves the city's southwest side and continues on to Laredo, the busiest US-Mexico border crossing for trucks. This corridor is also an important component in the continuing development of Port San Antonio.

This segment serves downtown San Antonio, Market Square, the University of Texas at San Antonio downtown campus, the San Antonio Produce Market, South Park Mall, Palo Alto College, Texas A&M University at San Antonio, the Toyota assembly plant and adjacent suppliers, and a growing logistics and industrial area at Loop 410 as well as the cities of Von Ormy and Somerset. Commercial and industrial development fronts the freeway near downtown. Residential and some commercial development lines the corridor south of US 90 to Somerset Rd. Mostly undeveloped land takes over south of Somerset Rd. to Loop 410. South of Loop 410, light industrial areas and two rail yards sit on the west side of the freeway between Loop 410 and Von Ormy.

Roadway details


Click here for a schematic of I-35 South.
  • 8 lanes from I-10 West to Laredo St. with a short double-decked stretch (4 lanes on the upper levels; 4 lanes on the lower level) from Guadalupe St. to S. Alamo St.
  • 9 lanes (4 southbound, 5 northbound) from Laredo St. to US 90
  • 6 lanes from US 90 to Spur 422/Poteet-Jourdanton Hwy.
  • 4 lanes from Spur 422/Poteet-Jourdanton Hwy. to Loop 1604

I-35 lanes map

  • No traditional access roads along most of the route from I-10 West to US 90, although S. Pecos-La Trinidad functions a southbound access road from I-10 West to S Alamo St. Short sections of access road exist on both sides between S Alamo St. and Cevallos St. A short access road exists southbound from San Marcos St. to Nogalitos.
  • Continuous access roads along most of remainder of route
  • Access roads do not continue through Loop 410 interchange or over the Medina River

I-35 access roads map


Click here for a list of I-35 South exits.

  • 60 mph from I-10 West to Loop 410
  • 70 mph from Loop 410 to Loop 1604

I-35 speed limit map

  • Double-decked freeway from just north of S. Alamo to just south of S. Laredo St.
  • TransGuide coverage from I-10 West to Southcross Blvd.
  • VIA Metropolitan Transit Madla Transit Center/Park & Ride just north of Zarzamora St.
  • Northbound left exit to Loop 353
  • Two miles of I-10/US 87 concurrent (multiplexed) from I-10 West to US 90
    • US 81 was concurrent (multiplexed) over I-35 in Bexar County before it was decommissioned south of Ft. Worth in 1991

I-35 special features map


Generally heavy from I-10 West to SW Military Dr. Moderate to light volumes south from there. Regular peak-period congestion can be found northbound in the morning between Division Ave. and Cesar Chavez Blvd. and in the evening in both directions between I-10 West and US 90.

Overall, the corridor has generally seen traffic growth over the past decade with the biggest increases south of Military Dr.

Traffic volume legend

I-35 traffic map


LOCATION 1990 2007 2010 2015 2016 2017 '07-'17
S of Laredo St.79,000180,000159,000173,964178,839177,327-1.49%
S of US 9092,000151,000135,000152,614155,370155,113+2.72%
N of SW Military Dr.59,000107,00077,000113,122117,525115,550+7.99%
Zarzamora St.34,00078,00068,00080,92484,65986,663+11.11%
Somerset Rd.18,80042,00038,00045,89247,84749,228+17.21%
N of New Laredo Hwy.17,00038,00035,00043,67745,57946,774+23.09%
S of Fischer Rd.21,00040,00042,00054,74156,00357,722+44.31%

Media gallery

Click here for photos and video of this freeway.

Construction projects

No current projects in this corridor.

Future plans

The MPO's 25-year plan has proposals for the expansion of I-35 to eight lanes from US 90 to the Atascosa County line.

A new expressway (Kelly Parkway) roughly paralleling this section of I-35 is proposed as part of the Port San Antonio long-range road improvements package. It would run north from SH 16 near the Toyota plant to US 90 via General Hudnell Dr., crossing I-35 between Spur 422 and Loop 410.

A fully-directional "stack" interchange at Loop 410 is included in future plans to upgrade SW Loop 410.


I-35 designation authorized on October 1, 1959, and was originally called the "Southwest Expressway." It's now named the PanAm Freeway because it is an unofficial segment of the Pan American Highway. This freeway is also part of the so-called "NAFTA Superhighway".

The section from Guadalupe to Pruitt St. (near Nogalitos) was completed in 1952. The elevated segment from Guadalupe to present-day I-10 West was completed by 1957. There were two proposals for the section from Nogalitos to Loop 410, including one that would have usurped Nogalitos and New Laredo Hwy. and another that would have doglegged along SW Military Dr. The final routing was approved by 1955 and the access roads were opened between SW Military and New Laredo Hwy. in 1956. The expressway between Nogalitos and Division opened in 1958. The section from SW Military south to New Laredo Highway was upgraded to a full freeway in 1960.

The section from I-10 West to US 90 was expanded in the late '80s and early '90s. The section from SW Military to Spur 422 was expanded from four to six lanes around 1989. TransGuide coverage was added to the section from I-10W to Southcross in 1995. The section from US 90 to SW Military was reconstructed ca. 2009. The reconstruction removed several pedestrian bridges, expanded the overpasses and frontages roads, and relocated several entrance and exit ramps. The section from Zarzamora to Somerset Rd. was reconstructed during the same time frame. That project removed the previous southbound left-hand exit to SP 422 and the northbound left-hand exit to Palo Alto Rd., extended the northbound frontage road through the Spur 422 interchange, and adjusted several roadways and ramps in the vicinity.

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This page and all its contents are Copyright 2019 by Brian Purcell

The information provided on this website is provided on an "as-is" basis without warranties of any kind either express or implied.  The author and his agents make no warranties or representations of any kind concerning any information contained in this website.  This website is provided only as general information.  The author expressly disclaims all liability with respect to actions taken or not taken based upon the information contained herein or with respect to any errors or omissions in such information.  All opinions expressed are strictly those of the author.  This site is not affiliated in any way with any official agency.