Interstate 37
Interstate 37 (I-37) is a 143-mile (230 km) north–south Interstate Highway entirely within the southern portion of the U.S. state of Texas, connecting the Gulf Coast city of Corpus Christi with San Antonio.[1][2] The route begins at its southern terminus with an interchange serving Interstate 69 (I-69) and U.S. Highway 77 (US 77) on the northwest side of Corpus Christi and proceeds generally northward through rural and semi-rural areas of the Coastal Bend region before entering the southeastern suburbs of San Antonio, where it meets its northern terminus at I-35 southeast of downtown.[3][2] Designated as part of the Interstate Highway System in 1959, I-37 largely replaced segments of the earlier State Highway 9 (SH 9) and shares short concurrencies with US 281 near Three Rivers and Pleasanton.[2] Construction commenced in the 1960s within the urban areas of Corpus Christi and San Antonio, with rural sections completed by the 1980s, resulting in a primarily four-lane divided freeway standard throughout its length.[2] The highway features intermittent frontage roads along about 65% of its corridor and maintains posted speed limits of 70–75 mph (113–121 km/h), though segments near urban centers experience higher traffic volumes and occasional congestion.[3][2] As a key component of the National Highway System and the Strategic Highway Network, I-37 facilitates critical freight transport to and from the Port of Corpus Christi—one of the busiest U.S. seaports—while providing essential access to San Antonio International Airport and supporting regional commerce in agriculture, energy, and manufacturing.[2] It also serves as a primary hurricane evacuation route for coastal communities, with dedicated contraflow operations and emergency shoulder lanes activated during major storms to expedite northward travel.[4][5] Ongoing improvements, including bridge replacements and lane widenings, address safety concerns, mobility bottlenecks, and increasing truck traffic, with annual average daily traffic ranging from about 18,000 vehicles in rural stretches to over 82,000 in urban zones as of 2015.[6][2]Overview
Route summary
Interstate 37 (I-37) is a 143-mile (230 km) Interstate Highway entirely within the U.S. state of Texas, serving as a key north–south corridor in the southern portion of the state.[1] The route primarily connects the Gulf Coast ports around Corpus Christi to the urban center of San Antonio, facilitating freight movement and regional travel.[7] The highway's southern terminus is an interchange with Interstate 69/U.S. Highway 77 (I-69/US 77) northwest of Corpus Christi, where it provides access to the Port of Corpus Christi and coastal areas.[3] From there, I-37 heads northwest through rural and semi-urban landscapes, intersecting major routes such as U.S. Highway 281 before reaching its northern terminus at an interchange with Interstate 35 (I-35) and US 281 in San Antonio.[7] This positioning makes I-37 a vital link for evacuations during Gulf Coast hurricanes.[7] Designated as part of the Interstate Highway System in 1959 and incorporated into the Texas Interstate Highway System in 1962, I-37 was planned to enhance connectivity between coastal trade hubs and inland economic centers.[8][7]Regional significance
Interstate 37 plays a crucial role in connecting the Port of Corpus Christi, a major U.S. port and the largest energy export gateway, to San Antonio's commercial districts, including downtown areas like the River Walk and the Alamodome. This linkage supports the efficient movement of goods from the Gulf Coast shipping and oil hub to inland markets, enhancing regional trade flows in South Texas.[9][7][2] The highway facilitates freight transport for key sectors including agriculture, energy, and manufacturing across the counties it traverses, such as Nueces, San Patricio, Bee, Live Oak, Atascosa, and Bexar. In energy, it provides direct access for refineries and petrochemical operations, notably in San Patricio County, home to one of the nation's largest refineries. For agriculture and manufacturing, I-37 enables the distribution of South Texas produce and industrial products to broader markets, contributing to the economic vitality of these rural and urban areas as part of the national Primary Freight Network. Daily traffic volumes average 50,000 to 100,000 vehicles near urban centers like Corpus Christi and San Antonio, with truck traffic comprising up to 17% in port-adjacent segments (as of 2015).[10][2][11] As a primary evacuation route for Gulf Coast hurricanes, Interstate 37 incorporates contraflow lanes and emergency shoulder usage to increase capacity during storms, serving approximately 600,000 residents in the Coastal Bend region (as of 2024). Its integration with the Interstate 69 system, particularly through US 281 (designated as future I-69 to Laredo), strengthens the north-south corridor for both routine commerce and crisis response, linking South Texas to international border trade routes.[4][12][7][13]Route Description
Corpus Christi metropolitan area
Interstate 37 begins at its southern terminus in downtown Corpus Christi at an interchange with U.S. Highway 181 and State Highway 35, where it initially follows a freeway alignment concurrent with US 181 in the northbound direction.[7] The recent completion of the US 181 Harbor Bridge replacement project in June 2025 has reconstructed portions of this initial segment, providing improved elevated access to the city's central business district, nearby maritime facilities, and the Port of Corpus Christi via new interchanges and the taller cable-stayed bridge.[14] Speed limits in this area are typically reduced to 55–65 mph to accommodate heavier traffic volumes and frequent interchanges.[15] As I-37 progresses north from downtown, it traverses industrial corridors adjacent to the Port of Corpus Christi and along the western shores of Nueces Bay, passing refineries and petrochemical plants that form a key part of the region's economy. The route features elevated sections and bridges over local waterways and rail lines, facilitating efficient movement around the bayfront infrastructure. A prominent interchange occurs at the Crosstown Expressway (SH 358), which connects to the port area and Padre Island beaches to the east. Further north, the highway intersects Spur 544 (Navigation Boulevard), serving commercial districts and additional industrial access points.[16][17] Continuing through the northern suburbs, I-37 navigates around Calallen, a residential and commercial enclave in northern Nueces County, with overpasses spanning rail yards and arterials like Business US 77. Entering San Patricio County, the freeway maintains its four-lane divided profile, crossing agricultural fringes before reaching the major interchange with US 77 near Sinton at exits 14A/B (mile markers 14–17). This junction marks the transition from the urban metropolitan environment to more rural terrain, with access points providing connectivity to nearby refineries and coastal recreational areas.[18][3]Rural central section
Interstate 37's rural central section begins north of the US 77 interchange in San Patricio County and extends northward through Bee County, Live Oak County, and the southern portion of Atascosa County, covering approximately mile markers 17 to 110. This segment primarily traverses sparsely populated areas characterized by agricultural fields, ranchland, and brush country typical of South Texas. The highway maintains a four-lane divided freeway configuration with frontage roads present in varying segments, facilitating local access via farm-to-market roads and short spurs.[2] As it progresses, I-37 passes west of Beeville in Bee County via the interchange at exit 56 with U.S. 59, providing access eastward to the city, followed by access to George West westward in Live Oak County. The route continues through ranchland-dominated terrain near George West, with limited development and occasional three-digit spurs offering connections to nearby communities and facilities. Traffic volumes remain low, with average annual daily traffic (AADT) typically under 20,000 vehicles, including 16–28% trucks, reflecting the rural nature of the corridor.[19][2] The terrain shifts from flat coastal plains in the southern portions, near the Nueces River crossing south of Mathis, to gently rolling hills further north, with the highway elevated in flood-prone areas along waterways like Sulphur Creek and the Atascosa River. Wildlife crossings are incorporated to mitigate impacts on local fauna in this brushy, semi-arid landscape, and speed limits are posted at 75 mph for most of the section, dropping to 70 mph in select areas with higher crash risks. Services are sparse, with a safety turnout available near mile marker 42 outside Mathis and a full rest area at mile marker 78 north of Three Rivers in Live Oak County, providing picnic areas, restrooms, and parking for travelers.[2][20][15]San Antonio metropolitan area
Interstate 37 enters Bexar County from Atascosa County near mile marker 118, just north of Pleasanton, where the route transitions from rural landscapes to increasingly urban development characterized by the addition of frontage roads to facilitate local access and navigation through growing suburban areas.[2] As it progresses northward, the highway features a six-lane divided configuration with intermittent frontage roads covering approximately 47 to 52 percent of the segment, supporting traffic flow amid expanding residential and commercial zones south of San Antonio.[2] The route interchanges with US 281—designated as the future alignment for Interstate 69—near the Loop 1604 junction at mile marker 125, providing connectivity to the city's outer beltway before approaching the Interstate 410 interchange at mile marker 134 on San Antonio's southeast side.[21][2] From there, I-37 passes through mixed residential and commercial districts, offering direct access to key sites such as the redeveloped Brooks City-Base area and proximity to the Alamodome, a major multipurpose arena in the southeastern urban core.[22] This segment, spanning mile markers 125 to 134, experiences significant congestion, with volume-to-capacity ratios reaching 0.99 during peak hours in 2015 and projected to exceed 1.40 by 2040 due to regional growth.[2] Nearing downtown, I-37 interchanges with Interstate 10 at mile marker 141, serving as a critical link for east-west travel without a direct concurrency, before terminating at its northern end with Interstate 35 and US 281 at mile marker 143.[23] In this urban stretch from mile markers 134 to 143, the highway integrates with the denser city grid, with frontage roads aiding mobility for the approximately 55,400 vehicles per day at the I-410 junction as of 2015.[24][25] The route's design here emphasizes efficient merging into the I-35/US 281 corridor, which continues northward as a major artery toward San Antonio International Airport.[22]History
Planning and designation
Interstate 37's planning originated within the framework of the national Interstate Highway System, proposed by President Dwight D. Eisenhower in 1955 and authorized by the Federal-Aid Highway Act of 1956, which established a 41,000-mile network funded primarily through federal gasoline taxes.[26] This legislation included Texas's initial allocation of approximately 2,905 miles of interstate highways, with I-37 proposed as a key southern route to connect inland urban centers to coastal ports.[27] The highway was formally added to the Interstate system in October 1957 by the Bureau of Public Roads, designating it to span from San Antonio southward to Corpus Christi, facilitating economic ties to the Gulf of Mexico and serving military and evacuation needs.[7] Designation of the specific route occurred in 1959, when the Texas Transportation Commission authorized I-37 along a primarily new alignment that paralleled U.S. Highway 181 and replaced segments of State Highway 9 between Corpus Christi and Three Rivers, while supplanting portions of U.S. Highway 281 further north toward San Antonio.[15][28] This path was selected to leverage existing corridors like US 181 for efficiency, avoiding more circuitous alternatives that could traverse wetlands or less developed areas, such as potential routes through Victoria. The Federal Highway Administration (FHWA) and American Association of State Highway Officials (AASHO, predecessor to AASHTO) endorsed the numbering and alignment in coordination with state planners, ensuring compliance with interstate design standards.[7] Initial funding for I-37 stemmed from the Interstate Highway Cost Act of 1956, which created the Highway Trust Fund to cover 90% of construction costs federally, with the Texas Highway Department (now TxDOT) overseeing the remaining 10% and managing route planning, right-of-way acquisition, and coordination with local authorities.[27] Early planning also addressed environmental challenges, particularly the crossing of Nueces Bay near Corpus Christi, where designs incorporated elevated structures to navigate coastal wetlands and tidal areas without extensive disruption, reflecting preliminary engineering considerations before modern environmental regulations.[2]Construction phases
Construction of Interstate 37 commenced in the urban areas of Corpus Christi and San Antonio during the 1960s, with rural segments following in the 1970s and early 1980s. The highway's development aligned with the broader Interstate System expansion in Texas, utilizing portions of existing routes like SH 9 and US 281 as temporary alignments until full freeway standards were met. By 1972, approximately 44% of the route was complete, including key connections in both metropolitan areas.[2][7] The initial phase focused on Corpus Christi, where ground was broken in 1961 for the first segment from US 181 near Broadway Street to SH 358 (South Padre Island Drive). This urban section, routed between Antelope and Buffalo Streets north of Leopard Street, addressed growing traffic needs in the port city and integrated with the recently opened Harbor Bridge on US 181. Construction extended northward from this segment through the 1960s, reaching FM 534 at Swinney Switch by 1972 and establishing the southern terminus of the freeway.[29][7] In San Antonio, building began in the mid-1960s amid local planning for the city's expressway network. The first openings occurred in 1967, with segments from Florida Street to I-10 and from SE Military Drive to US 181 becoming operational. The connecting portion from I-10 to SE Military Drive followed in 1968, while the Loop 410 interchange was finished in 1969. The downtown link from Florida Street to I-35, incorporating the complex I-10 interchange, was completed in 1972 at a cost of $11 million, marking a major milestone in the urban build-out. By that year, the route extended south from San Antonio to FM 1303 near present-day Loop 1604.[15][7] Rural construction advanced in the 1970s, particularly through Bee and Live Oak counties between the metropolitan endpoints. The segment from US 181 to Loop 1604 opened in 1974, bridging much of the central gap and facilitating travel along the former SH 9 corridor. Remaining rural stretches, including bridges over waterways like the Nueces River, were finalized in the early 1980s, with the northbound Nueces River bridge originally built in 1958 and widened in 1986 to accommodate additional lanes. The entire 143-mile route achieved full interstate standards and signage by 1983.[15][30]Developments
Recent projects
The replacement of the Harbor Bridge in Corpus Christi has necessitated multiple closures and lane reductions on Interstate 37 from 2024 through 2025 to accommodate construction activities. A significant northbound closure from North Tancahua Street to the Crosstown Interchange (SH 286) occurred from August 14, 2025, until fall 2025, with traffic detoured to the frontage road via Port Avenue for restoration and paving work.[31] Additional temporary measures included nightly full closures of northbound I-37 mainlanes from Port Avenue to Nueces Bay Boulevard in June 2025 and intermittent daytime reductions near the south interchange in April 2025, all aimed at finalizing bridge connections and surface treatments.[31][32] Further upstream in the Corpus Christi metropolitan area, the Texas Department of Transportation (TxDOT) is widening I-37 from Redbird Lane to the US 77 interchange, a 2.3-mile segment that includes replacing the aging bridges over the Nueces River to improve flood resilience and storm surge capacity.[6] Construction on this $85.7 million project began in September 2021, with the third phase starting in September 2024 to expand mainlanes to four in each direction, add wider shoulders, rebuild the northbound I-37 bridge over US 77, and reconfigure entrance and exit ramps.[6][33] The project is expected to be completed in early 2027.[34][35] In the San Antonio area, TxDOT proposed a $40 million upgrade to the interchange at I-37 and SE Military Drive (SL 13) near Brooks City-Base to alleviate congestion and enhance safety.[36] The project features a conversion to a diverging diamond interchange, a new southbound overpass (flyover) for direct access to Brooks City-Base, an extended frontage road transitioning to an auxiliary lane, and 10-foot shared-use paths for pedestrians.[36][37] Public input was solicited via in-person and virtual open houses on August 28, 2025, with comments accepted until September 12, 2025; construction remains pending environmental clearance and funding approval.[37][38] Pavement rehabilitation efforts in Bee County focused on resurfacing sections of I-37 in 2024 as part of TxDOT's statewide maintenance program to extend roadway life and improve ride quality.[39] Following TxDOT safety audits initiated in 2022 under the Highway Safety Improvement Program (HSIP), enhancements were added to rural sections of I-37, including centerline and shoulder rumble strips to alert drivers of lane departures and upgraded lighting at high-risk curves and intersections to reduce nighttime crashes.[40][41] These measures, prioritized in the 2022-2027 Texas Strategic Highway Safety Plan, target run-off-road incidents common in undivided rural corridors and have been implemented systemically along I-37 between the metropolitan areas.[41][42]Future plans
The Texas Department of Transportation (TxDOT) completed an updated I-37 Corridor Study in 2023, covering the route from I-69E in Corpus Christi to I-410 in San Antonio, to identify deficiencies and prioritize improvements for enhanced freight mobility and overall capacity.[43] The study recommends potential mainline widening to address growing traffic volumes and support regional commerce, though specific high-occupancy vehicle (HOV) lane extensions remain under evaluation in subsequent planning phases.[2] A proposed South Texas Parkway would create a 15-mile freeway connector linking Interstate 35 (I-35) to Interstate 37 (I-37) south of Loop 410 in San Antonio, aimed at improving regional connectivity amid rapid south-side development.[44] Planning advanced in 2025 with an amendment to the Alamo Area Metropolitan Planning Organization's Major Thoroughfare Plan, classifying the alignment as a freeway with widths of 250 to 500 feet; on November 5, 2025, a city committee endorsed the amendment, though concerns were raised regarding public notice and property impacts.[45][46] Environmental review and right-of-way acquisition are pending as part of the project's early stages. Estimated at $1.5 billion, the initiative draws support from local stakeholders for its role in alleviating congestion near major employers like the Toyota Motor Manufacturing Texas plant.[47] Interstate 37's alignment supports the broader Interstate 69 (I-69) system in Texas, with ongoing designations along concurrent U.S. Highway 281 (US 281) north of San Antonio expected to advance toward full interstate standards by 2030, incorporating intelligent transportation systems for traffic management.[48] Over 172 miles of the I-69 network, including segments tied to I-37's southern terminus at I-69E, have already received interstate signage, with future upgrades focusing on safety and technology integration to complete the corridor.[49] TxDOT's 2025 Statewide Transportation Resilience Plan highlights vulnerabilities of coastal infrastructure, including bridges in the Corpus Christi District, to sea-level rise projected at three to seven feet by 2100, recommending elevated designs for flood-prone areas along evacuation routes like those near Corpus Christi bays.[50] These resilience measures, including potential elevation of low-lying sections, align with 2024 federal grant opportunities under programs like the National Coastal Resilience Fund, though site-specific funding for I-37 remains in early proposal stages.[51] Major widening projects along I-37, such as those identified in the corridor study, carry planning-level cost estimates ranging from hundreds of millions to over $1 billion per segment, with funding anticipated through a mix of federal programs like the National Highway Performance Program and state-issued bonds.[22]Interchanges
Major junctions
Interstate 37's southern terminus is at a directional T interchange with US 181 and SH 35 in Corpus Christi, serving as a critical gateway for traffic accessing the Port of Corpus Christi, one of the largest ports in the United States by cargo volume.[7][52] This configuration facilitates efficient connections for freight and passenger vehicles, with ongoing reconstruction under the US 181 Harbor Bridge Replacement Project enhancing ramp alignments and resilience to coastal flooding.[52] In the central rural section, the interchange with US 59 near Beeville is a diamond configuration that links I-37 to the east-west corridor toward Victoria and Houston, supporting regional commerce and agriculture in the Coastal Bend area.[19] Further north, the half-diamond interchange with US 281 south of San Antonio integrates with the future designation of Interstate 69, enabling seamless transitions for northbound traffic toward Johnson City and the Texas Hill Country.[7][2] Approaching the San Antonio metropolitan area, I-37 meets I-410 at a four-level stack interchange on the southeast side, originally planned as a cloverleaf but upgraded for higher capacity to connect with the city's beltway system and facilitate circumferential travel around urban congestion.[15] Near downtown, I-37 intersects I-10 at a wye-style configuration, serving as an east-west connector for cross-state routes while handling heavy commuter and freight volumes in this urban distributor segment.[7] The route briefly concurs with I-10 over approximately one mile before diverging, optimizing access to central San Antonio amenities.[15] The northern terminus occurs at a multi-level stack interchange with I-35 and US 281 in downtown San Antonio, where I-37 merges into the concurrent I-35/US 281 corridor, forming a vital linkage for traffic distributing to northern Texas and beyond.[7] Throughout its length, most major junctions feature diamond or partial cloverleaf designs for cost-effective rural and suburban access, with recent upgrades including ramp reconfigurations at the US 77 interchange near Corpus Christi to improve safety and throughput amid hurricane evacuation demands.[2][6]Exit list
The exit list for Interstate 37 is presented in the table below, organized by county from south to north along the route. Exit numbers correspond to mileposts from the southern terminus in Corpus Christi, with the highway spanning approximately 143 miles to its northern terminus in San Antonio. The table includes exit numbers, approximate mileposts (based on the mile-based numbering system), destinations served, and notes for direction-specific access, business routes, frontage road connections, and other details such as three-digit spurs or recent changes from post-2020 TxDOT projects. Bidirectional exits are standard unless noted otherwise; some urban exits in Nueces and Bexar counties have separate southbound/northbound numbering due to local configurations.[53]| County | Location | mi | Exit | Destinations | Notes |
|---|---|---|---|---|---|
| Nueces | Corpus Christi | 1 | 1A-B | Port Ave; Brownlee Blvd; Buffalo St | Southbound split; access to downtown Corpus Christi |
| Nueces | Corpus Christi | 1 | 1C | TX 286 (MM 1.0) | Crosstown Expressway; bidirectional |
| Nueces | Corpus Christi | 1 | 1D-E | Port Ave; Nueces Bay Blvd; Lawrence Dr | Southbound Port Ave; northbound Lawrence Dr; industrial access |
| Nueces | Corpus Christi | 2 | 2 | Up River Rd | Frontage road access southbound |
| Nueces | Corpus Christi | 3 | 3A | Navigation Blvd | Bidirectional |
| Nueces | Corpus Christi | 3 | 3B | McBride Ln; Lantana St | Northbound only |
| Nueces | Corpus Christi | 4 | 4A | TX 358 | SPID; Corpus Christi major arterial |
| Nueces | Corpus Christi | 4 | 4B | Lantana St; McBride Ln | Southbound only |
| Nueces | Corpus Christi | 5 | 5 | Corn Products Rd; Valero Way | Industrial area access |
| Nueces | Corpus Christi | 6 | 6 | I-37 Frontage Rd; Service Rd | Frontage road connection |
| Nueces | Corpus Christi | 7 | 7 | Suntide Rd; Tuloso Rd | Local access |
| Nueces | Corpus Christi | 9 | 9 | Up River Rd; FM 2292; Rand Morgan Rd | Bidirectional |
| Nueces | Corpus Christi | 10 | 10 | Carbon Plant Rd; Joe Fulton Corridor | Industrial; northbound Carbon Plant |
| Nueces | Corpus Christi | 11 | 11A | I-37 Frontage Rd; McKinzie Rd; FM 3386 | Frontage and local roads |
| Nueces | Corpus Christi | 11 | 11B | Violet Rd; Hart Rd; FM 24 | Northbound only |
| Nueces | Corpus Christi | 13 | 13A | Leopard St; Callicoatte Rd; FM 1694 | Southbound Leopard St |
| Nueces | Corpus Christi | 13 | 13B | Interstate 37 Access Rd; Sharpsburg Rd | Northbound access rd |
| Nueces | Corpus Christi | 14 | 14A | I-69E / US 77 (MM 14.0) | Major junction to Robstown/Kingsville southbound |
| Nueces | Corpus Christi | 14 | 14B | Redbird Ln; Sharpsburg Rd | Local access; northbound Redbird |
| Nueces | Corpus Christi | 16 | 16 | Labonte Park | Park access |
| Nueces | Odem | 17 | 17 | US 77 N; Sinton; Victoria | Continuation north; picnic area nearby |
| San Patricio | Odem | 20 | 20B | Cooper Rd | Local rural access |
| San Patricio | Edroy/Odem | 22 | 22 | TX 234; FM 796; Edroy | Bidirectional |
| San Patricio | Sinton | 31 | 31 | TX 188; Sinton; Rockport | Access to Bus. US 181 in Sinton |
| San Patricio | Mathis | 34 | 34 | TX 359 Spur; Mathis; Alice | Business spur to downtown Mathis |
| San Patricio | Mathis | 36 | 36 | TX 359; Skidmore; Mathis | Continuation to Bee County |
| San Patricio | Mathis | 40 | 40 | FM 888 | Local access |
| Bee | Skidmore/Mathis | 42 | 42 | Bus. US 59; Beeville | Business route through Beeville |
| Bee | Beeville | 45 | 45 | FM 673 | Frontage road access |
| Bee | Beeville | 47 | 47 | FM 534; Swinney Switch | Rural access |
| Bee | Beeville | 56 | 56 | US 59; Beeville; George West | Major junction; access to Bus. I-37 |
| Bee | George West | 59 | 59 | FM 799 | Local access; transition to Live Oak |
| Live Oak | George West | 61 | 61 | FM 3024 | Rural; Swinney Switch area |
| Live Oak | George West | 65 | 65 | FM 1358; Oakville; Three Rivers | Bidirectional |
| Live Oak | Three Rivers | 69 | 69 | TX 72; Kenedy; Three Rivers | Major east-west connection |
| Live Oak | Three Rivers | 72 | 72 | US 281 S; Three Rivers; Alice | South to Alice |
| Live Oak | Three Rivers | 76 | 76 | FM 2049; US 281 Alt; Whitsett | Alternate US 281; rest area at MM 78 northbound |
| Live Oak | Whitsett | 83 | 83 | FM 99; Whitsett; Karnes City | Local and county access |
| Live Oak | Campbellton | 88 | 88 | FM 1099; Campbellton | Rural access |
| Atascosa | Campbellton | 91 | 91 | US 281 N | North to Pleasanton |
| Atascosa | Pleasanton | 98 | 98 | FM 541; McCoy; Poth | Local rural roads |
| Atascosa | Pleasanton | 103 | 103 | US 281 N; Pleasanton | Direct to downtown Pleasanton |
| Atascosa | Pleasanton | 104 | 104 | TX 199 Spur; Leal Rd | Spur to local areas |
| Atascosa | Pleasanton | 106 | 106 | Coughran Rd | Frontage road access |
| Atascosa | Pleasanton | 109 | 109 | TX 97; Floresville; Pleasanton | East to Floresville; picnic area nearby |
| Atascosa | Pleasanton | 113 | 113 | FM 3006 | Local access |
| Atascosa | Pleasanton | 117 | 117 | FM 536 | Rural connection |
| Bexar | San Antonio | 120 | 120 | Hardy Rd | Southern Bexar access |
| Bexar | San Antonio | 122 | 122 | Mathis Rd; Priest Rd | Local urban roads |
| Bexar | Elmendorf | 125 | 125 | Loop 1604; Anderson Loop; Elmendorf | Outer loop access |
| Bexar | San Antonio | 127 | 127 | San Antonio River Turnaround | U-turn and river access |
| Bexar | Elmendorf | 130 | 130 | Donop Rd; Southton Rd | Local; near river walk attractions |
| Bexar | San Antonio | 132 | 132 | Spur 122 | Three-digit spur to local areas |
| Bexar | San Antonio | 135 | 135 | Loop 13 (SL 13); Military Dr; Stinson Airport; Brooks City-Base | Urban arterial |
| Bexar | San Antonio | 136 | 136 | Pecan Valley Dr | Access to state facilities |
| Bexar | San Antonio | 137 | 137 | Hot Wells Blvd | Local access |
| Bexar | San Antonio | 138 | 138A | Southcross Blvd E | Eastbound urban |
| Bexar | San Antonio | 138 | 138B | New Braunfels Ave W; Southcross Blvd W | West side split |
| Bexar | San Antonio | 138 | 138C | Fair Ave; Hackberry St | Northbound only |
| Bexar | San Antonio | 140 | 140A | Carolina St; Florida St | Downtown approach |
| Bexar | San Antonio | 140 | 140B | Cesar E. Chavez Blvd; Alamodome; Hemisfair | Convention and sports district |
| Bexar | San Antonio | 141 | 141A | Commerce St; Downtown; Convention Center | Amtrak and convention access |
| Bexar | San Antonio | 141 | 141B | Houston St; The Alamo | Historic district |
| Bexar | San Antonio | 141 | 141C | McCullough Ave; Nolan St; Brooklyn Ave | Northern urban split |
| Bexar | San Antonio | 142 | 142A | I-35 N; Austin | Northern terminus approach |
| Bexar | San Antonio | 142 | 142B | I-35 S; Laredo | Left exit southbound |
| Bexar | San Antonio | 143 | 143 | I-10; US 90; US 87; Houston/El Paso | Major junction at northern end |