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San Antonio Area Freeway System
Interstate 37
(Lucian Adams/Wm. Bordelon Fwy)

This page last updated February 5, 2024

I-37 highlight map
I-37 highlight map

This page covers Interstate 37 east and south of downtown San Antonio from I‑35 to US 181. This freeway continues north of downtown as US 281 North.

Length: 11 miles



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On this page:

Overview Roadway
details
Lanes Access
roads
       
Exits Speed
limits
Special features
and notes
Traffic
       
Media
gallery
Construction
projects
Future
plans
History
       

Overview

Interstate 37 serves San Antonio's southeast side and diverges with US 181, the main link to exurban Wilson County. The freeway provides access to downtown San Antonio, the Alamodome, St. Paul Square, the Brooks redevelopment (formerly Brooks City-Base), the San Antonio Missions Trail National Park, Texas DPS Regional Headquarters, San Antonio State Hospital, and San Antonio State School. The freeway is also a primary route to the Eagle Ford oilfields south and southeast of the city.

Between downtown and SE Military Dr., the freeway is fronted mostly by residential areas. From there to US 181, most of the immediate frontage is undeveloped.


Roadway details

LANES
I-37 lanes map
  • 8 lanes between I‑35 and S. New Braunfels Ave. with a short six lane stretch through the I‑10 interchange
  • 6 lanes between New Braunfels Ave. and SE Military Dr.
  • 4 lanes between SE Military Dr. and Loop 410
  • 5 lanes (3 northbound, 2 southbound) between Loop 410 and US 181
I-37 lanes map
   
ACCESS ROADS
I-37 access roads map
  • There are no continuous access roads along this freeway.
  • Short sections of access road exist at the following locations:
    • Between Cesar Chavez Blvd. and Commerce St.
    • Between Florida St. and Carolina St.
    • Between Hackberry St. and Fair Ave.
    • Along the west side of the freeway from S Presa St. to Blue Wing Rd. (at US 181)
I-37 access roads map
   
EXITS

Click here for a list of I‑37 exits.
 
 
SPEED LIMITS
I-37 speed limit map
  • 60 mph between I‑35 and Brooklyn Ave.
  • 65 mph between Brooklyn Ave. and SE Military Dr.
  • 70 mph between SE Military Dr. and US 181
I-37 speed limit map
   
SPECIAL FEATURES AND NOTES
I-37 special features map
  • concurrent from I‑35 to Loop 410
  • TransGuide coverage along entire route
  • Northbound left exit to southbound I‑35
  • VIA Metropolitan Transit Brooks Transit Center south of SE Military Dr. just west of I‑37
I-37 special features map
   
TRAFFIC
I-37 traffic map

Heavy in the downtown area. Heavy to moderate south of I‑10.

Recurring morning congestion occurs northbound from I‑10 to I‑35 and also in the vicinity of Loop 410.


Traffic volume legend
I-37 traffic map
   
AVERAGE DAILY TRAFFIC
LOCATION 2002 2012 2017 2019 2021 2022 '12-'22
% CHG
S of I‑35 132,000 131,000 159,575 159,184 140,216 127,190 -2.91%
N of Cesar Chavez Blvd. 114,000 112,000 135,577 136,515 132,577 120,260 +7.38%
N of I‑10E         135,259 122,693 N/A
N of Fair Ave. 104,000 120,000 137,758 138,357 133,629 121,215 +1.01%
N of Hot Wells Blvd. 73,000 90,000 102,196 103,713 101,143 91,747 +1.94%
N of SW Military Dr. 57,000 76,000 113,023 86,136 83,950 76,151 +0.20%
N of Loop 410 46,000 62,000 88,867 74,157 86,872 69,731 +12.47%
S of Loop 410 57,000 69,000 82,801 84,749 91,941 83,400 +20.87%

(NOTE: In 2021, TxDOT changed the location of several traffic counting stations. New stations will show no history prior to 2021.)



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Media gallery

Click here for photos and video of this freeway.


Construction projects

There are currently no major construction projects in this corridor.


Future plans

TxDOT has plans to convert the I‑37/SE Military Dr. intersection to a Diverging Diamond Interchange (DDI) and add an exit to City Base Landing. That project is currently anticipated to start in 2025.

The Alamo Area Metropolitan Planning Organization has an unfunded proposal in its 25-year plan to expand I‑37 from four to six lanes from Loop 410 south to the Atascosa County line.


History

This route was originally named the "Southeast Expressway". The section south of I‑10 is was named in 1994 for Lucian Adams, and the section north of I‑10 is named for William J. Bordelon; both are World War II Medal of Honor recipients. Interstate 37 was authorized by the Texas Transportation Commission on October 1, 1959.

While all of San Antonio's other freeways have sections that were upgraded from existing US highways, I‑37 was entirely a "new location" route. US 181 was adjusted to end at I‑37 when it opened; it had previously continued into the city along S Presa St.

I-37 history map
I-37 history map
I-37 at Cesar Chavez looking SE in 1968

I‑37 at Cesar Chavez Blvd. looking SE in 1968
Note the parking lots for HemisFair being paved in the freeway right-of-way.
(Photo courtesy of TxDOT)

I-37 north of I-10 looking north in 1968

I‑37 north of I‑10 looking north in 1968
Workers installing HemisFair sign. This section of I‑37 lead directly into the HemisFair parking lot just past Florida St.
(Photo courtesy of TxDOT)

I-37 at Commerce looking north in 1971

I‑37 at Commerce St. looking north in 1971
(Photo courtesy of TxDOT)

Snippet of 1950 plan for I-37 at Loop 410

Snippet of 1950 plan for I‑37 at Loop 410
Note the planned cloverleaf interchange. This was changed in subsequent plans to the four-level "stack" interchange that's there today. Also note the absence of a route for I‑37 south of Loop 410; the routing for that section was still being finalized at this time.
(Document courtesy of TxDOT)

More historical photos of I‑37 are available here.