United States Border Patrol Interior Checkpoints
The United States Border Patrol operates 71 traffic checkpoints, including 32 permanent traffic checkpoints, near the southern border of the United States. The primary purpose of these inspection stations is to deter illegal immigration and smuggling activities. After 9/11 they took on the additional role of terrorism deterrence. These checkpoints are located between 25 and 75 miles of the Mexico – United States border along major U.S. highways. Their situation at interior locations allow them to deter illegal activities that may have bypassed official border crossings along the frontier. The checkpoints are divided among nine Border Patrol sectors: west to east, these are San Diego, El Centro, Yuma, Tucson, El Paso, Marfa, Del Rio, Laredo, and Rio Grande Valley.
There are a number of Border Patrol checkpoints in the northern states (such as New York or Maine), within 100 miles from the Canadian border.
Role of checkpoints 
The checkpoints are described as "the third layer in the Border Patrol's three-layer strategy", following "line watch" and "roving patrol" operations near the border. According to the U.S. General Accounting Office,
"Border Patrol agents at checkpoints have legal authority that agents do not have when patrolling areas away from the border. The United States Supreme Court ruled that Border Patrol agents may stop a vehicle at fixed checkpoints for brief questioning of its occupants even if there is no reason to believe that the particular vehicle contains illegal aliens. The Court further held that Border Patrol agents "have wide discretion" to refer motorists selectively to a secondary inspection area for additional brief questioning. In contrast, the Supreme Court held that Border Patrol agents on roving patrol may stop a vehicle only if they have reasonable suspicion that the vehicle contains aliens who may be illegally in the United States—a higher threshold for stopping and questioning motorists than at checkpoints. The constitutional threshold for searching a vehicle is the same, however, and must be supported by either consent or probable cause, whether in the context of a roving patrol or a checkpoint search."
List of permanent checkpoints 
Permanent Checkpoints along the Mexico-U.S. Border (listed in order from West to East)
- San Clemente - located 7 miles south of San Clemente on Interstate 5. --
- Temecula - located 24 miles north of Escondido on Interstate 15. --
- I-8 West - located 3 miles east of Pine Valley on Interstate 8. --
- Highway 94 - located 24 miles east of San Diego on California State Route 94. --
- Highway 78/86 - located just south of the intersection of California State Routes 78 and 86 on northbound side. --
- Highway 111 - located between Niland and Bombay Beach. --
- I-8 East - located 15 miles east of Yuma on Interstate 8. --
- I-19 heading North from Nogales, just north of Tubac.
- I-10 Heading West from Phoenix, just east of Blythe, California
- AZ Hwy 90 heading north from Whetstone to Benson --
- AZ Hwy 80 heading north from Tombstone to Benson (at junction with AZ 82 west, 31° 44' 57.28" N, 110° 5' 51.38" W).
- I-10 West - located 22 miles west of Las Cruces on Interstate 10. --
- Truth or Consequences - located 11 miles south of Truth or Consequences on Interstate 25. --
- US 70 East - located 50 miles east of Las Cruces on U.S. Route 70. --
- Alamogordo - located 30 miles south of Alamogordo on US Route 54. --
- Sierra Blanca - located 5 miles west of Sierra Blanca on Interstate 10. --
- Eagle Pass - located 11 miles east of Eagle Pass on U.S. Route 57. --
- Eagle Pass/Carrizo Springs - located 30 miles West Southwest of Eagle Pass, Texas on U.S. Route 277.
- Bracketville/Uvalde - located 60 miles east of Del Rio, Texas on Highway 90.
- Laredo - located 29 miles north of Laredo on Interstate 35. --
- Laredo 83 - located 35 miles north of Laredo on Highway 83. --
- Freer - located 16 miles west of Freer on U.S. Route 59. --
- Oilton - located 6 miles east of Oilton on Highway 359. --
- Falfurias - located 14 miles south of Falfurrias on U.S. Highway 281. --
- Sarita - located 14 miles south of Sarita on U.S. Route 77. --
- Hebbronville - located 1 mile south of Hebbronville on TX 16 S
- Hebbronville - located 50 yards south on FM 1017 at "T" intersection of Highway 285.
- Alpine - located 10 miles south of Alpine on Texas State Highway 118. --
- Brownsville - located on Boca Chica highway leading to Boca Chica Beach
Tactical checkpoints 
In fiscal year 2008 thirty-nine tactical checkpoints were in operation. Tactical checkpoints lack permanent buildings, and "support permanent checkpoints by monitoring and inspecting traffic on secondary roads that the Border Patrol determined are likely to be used by individuals in the country illegally or smugglers to evade apprehension at permanent checkpoints." A tactical checkpoint might consist of vehicles, traffic cones, signs, a portable water supply, a cage for canines (if deployed), and portable rest facilities.
Due to Congressional restrictions against the funding of permanent checkpoints in the Tucson sector, all of its checkpoints are tactical checkpoints. These were required to relocate every seven days, amended to every 14 days in 2005. Due to the need for road shoulder space and restrictions on placing checkpoints near curves, the number of sites is limited, and the relocation in practice means that checkpoints are periodically shut down. In 2005, the median tactical checkpoint nationally was active for 2 hours daily, as opposed to over 23 hours daily for permanent checkpoints; however the Tucson sector's checkpoint on Highway 19 was active 22 hours daily. A draft plan for the I-19 checkpoint in 2009 proposed to model it on the largest previous permanent checkpoint, the I-35 checkpoint north of Laredo, Texas, but would surpass it in size (18 acres) and inspection lanes (8 primary, 7 secondary). A number of community concerns were addressed, such as placement of canopies for dark sky restrictions for a local observatory, off-highway location, rumble strips, signage, and mitigation of traffic congestion. A community recommendation to "seek to mitigate noise" was to be "researched and considered".
Effectiveness and Criticisms 
The fairly comprehensive and aforementioned GAO report entitled BORDER PATROL assigns mixed success to border checkpoints. Positive results include the apprehension of nearly 17,000 persons in the country illegally at interior checkpoints in 2008. The report further states that, “More than 705,000 total Border Patrol apprehensions [occurred] along the southwest border in fiscal year 2008.” The Border Patrol also “encountered 530 aliens from special interest countries, which are countries the Department of State has determined to represent a potential terrorist threat to the United States.” There were also over 3,500 drug seizures at all southwest border checkpoints in 2008.
Staffing levels were substantially improved. The Laredo sector, for instance, increased its number of agents from 1200 in 2007 to approximately 1636 in 2008. Improved infrastructure and technology increased deterrence and detection capability in the Laredo sector. Improvements include cameras, license plate readers, and vehicle & cargo inspection systems (VACIS). Laredo also implemented a prosecution initiative in 2008. Named Operation Streamline, the goal was “to prosecute and remove all violators charged with illegal entry in target areas in the sector.”
A shortcoming cited by the same GAO report were the inaccuracies represented by the report’s title. The report states, “Our analysis showed that the actual checkpoint performance results were incorrectly reported for two of the three measures in fiscal year 2007 and for one measure in fiscal year 2008. As a result, the Border Patrol incorrectly reported that it met its checkpoint performance targets for these two measures.”
An analysis of the aforementioned GAO report criticized Border Patrol for its ineffective non-border checkpoints vs. actual border crossings. It stated, “There were 704,000 interdictions at actual border crossings in 2008; however, there were only 17,000 interdictions at internal non-border checkpoints. This 17,000 figure represents 2.4% of interdictions, but it took 4% of agents to accomplish this goal.” The analysis further states regarding the Tucson sector that, “Actual border interdictions numbered 320,000, but internal non-border checkpoint interdictions numbered 1,800. This means the number of interdictions per agent at the actual border was 116, but the number of interdicitons per agent at internal non-border checkpoints was only 8.” The analysis finally questions why the stated goal of DHS “is to detect and apprehend 30% of major illegal activity [at the border]." It asked why 70% of illegal activity is conceded at the actual border.
- "BORDER PATROL: Available Data on Interior Checkpoints Suggest Differences in Sector Performance". United States General Accounting Office. July 2005.
- "BORDER PATROL: Checkpoints Contribute to Border Patrol’s Mission, but More Consistent Data Collection and Performance Measurement Could Improve Effectiveness". United States General Accounting Office. August 2009.
- Woodard, Colin (January 9, 2011), "Far From Border, U.S. Detains Foreign Students", The Chronicle of Higher Education
- GAO cites: United_States_v._Martinez-Fuerte, 428 U.S. 543, 545 (1976)
- GAO cites: United_States_v._Martinez-Fuerte, 428 U.S. 563-564 (1976)
- GAO cites: United_States_v._Brignoni-Ponce, 422 U.S. 873, 881-882 (1975).
- GAO cites: United_States_v._Ortiz, 422 U.S. 891, 896-97 (1975).
- "Panoramio photo, US 70 East checkpoint". Panoramio.
- "U.S. Internal Checkpoints a Failure", Libertarian Party of Hawaii, Honolulu, April 2012.