Report to Congressional Requesters

United States Government Accountability Office

GAO

July 2005 BORDER PATROL

Available Data on 

Interior Checkpoints 

Suggest Differences in 

Sector Performance 

GAO-05-435 
What GAO Found

United States Government Accountability Office

Why GAO Did This Study

Highlights

Accountability Integrity Reliability

www.gao.gov/cgi-bin/getrpt?GAO-05-435.

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and methodology, click on the link above. 

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Highlights of GAO-05-435, a report to 

congressional requesters 

July 2005

BORDER PATROL

Available Data on Interior Checkpoints 

Suggest Differences in Sector 

Performance 

The Border Patrol operates 33 permanent traffic checkpoints in 8 of its 9 

sectors in the southwest border states, supported by tactical checkpoints. 

While permanent checkpoints have the advantage of physical infrastructure, 

tactical ones have the mobility to block routes used to evade permanent ones 

and to respond to intelligence on illegal activity. A third type of checkpoint 

operates in the Tucson, Ariz., sector, where the Patrol has been legislatively 

prohibited from funding construction of checkpoints since fiscal year 1999. 

This restriction has prevented checkpoint construction. The Patrol also began 

closing or relocating checkpoints in the sector every 7 days at the instruction 

of congressional staff in June 2002, and was legislatively required to relocate 

checkpoints on the same schedule in FY 2003 and 2004, and an average of once 

every 14 days in FY 2005. Three of six checkpoints in the sector had to close 

for 7/14 days, as safety considerations made it too hazardous to relocate them. 

Local law enforcement and business and community leaders we interviewed 

from communities near interior traffic checkpoints said that benefits resulting 

from checkpoint operations included reductions in crime and vandalism. 

Although a few cited traffic delays, most were supportive of checkpoint 

operations. However, some others were concerned about the impact of the 

checkpoints on traffic congestion and quality of life in their communities. 

The Border Patrol does not routinely evaluate the effectiveness of checkpoint 

operations, or their costs. The Patrol includes limited traditional performance 

measures in its Performance and Annual Report, such as apprehensions and 

contraband seized. GAO developed an apprehension per agent work year 

measure to assess performance. The data suggest that the performance of the 

Tucson sector interior checkpoints dropped starting in FY 2002, and more in 

FY 2003, after the Border Patrol began relocating or closing them on a regular 

basis. Three other sectors we visited that did not have to relocate or close 

checkpoints experienced no comparable decrease in apprehensions per agent 

work year during the same time period. Other factors not measured or 

accounted for might also have contributed to these outcomes, but the Border 

Patrol’s limited measures do not capture or assess them. A broader range of 

performance measures, when considered with other indicators, could be 

useful to CBP and the Congress as they consider ways to improve the 

effectiveness of interior traffic checkpoints and border security efforts. 

 

The U.S. Border Patrol, a 

component of the U.S. Customs 

and Border Protection (CBP) 

agency, a part of the Department of 

Homeland Security (DHS), aims to 

apprehend persons who illegally 

enter the United States between 

official ports of entry, including 

potential terrorists, aliens, and 

contraband smugglers, thereby 

deterring or stopping illegal 

activity. The Patrol operates 

permanent and tactical 

(temporary) interior traffic 

checkpoints on major and 

secondary U.S. roads, mainly in the 

southwest border states where 

most illegal entries occur, as part 

of a multi-layer strategy to 

maximize detection and 

apprehension of illegal entrants. 

This report addresses (1) the role 

of interior checkpoints in the 

Patrol’s strategy; (2) what is known 

about checkpoint costs and 

benefits; and (3) how checkpoints 

are evaluated and what 

performance measures indicate 

regarding their effectiveness. 

What GAO Recommends

To better gauge the effects of 

border control efforts, GAO 

recommends that the CBP 

Commissioner (1) develop 

additional performance measures 

for productivity and effectiveness 

of interior checkpoints, and (2) 

include data on checkpoint 

performance, and improvements 

that might be made, in CBP’s 

Performance and Annual Report. 

DHS concurred with the 

recommendations. 
Page i GAO-05-435 Border Patrol 

Letter 1

Results in Brief 5 

Background 10 

Permanent and Tactical Checkpoints Have Different but 

Complementary Roles in the Border Patrol Strategy 15 

Benefits and Costs of Traffic Checkpoints Are Difficult to Quantify, 

but Some Examples Are Available 29 

The Lack of Systematic Evaluation Limits the Border Patrol’s 

Ability to Allocate Resources Based on Need 38 

Conclusions 46 

Recommendations for Executive Action 47 

Agency Comments 47 

Appendix I Scope and Methodology 49 

Appendix II San Diego Sector Profile 55 

Appendix III Tucson Sector Profile 63 

Appendix IV Laredo Sector Profile 69 

Appendix V McAllen Sector Profile 77 

Appendix VI Comments from the Department of Homeland 

Security 83 

Appendix VII GAO Contact and Staff Acknowledgments 85 

Contents 
Page ii GAO-05-435 Border Patrol 

Table 

Table 1: Tucson Sector Nonpermanent Checkpoints Schedule to 

Conform to Legislative Language 27 

Figures 

Figure 1: Topography and Road Systems along the Southwest 

Border 11 

Figure 2: Total Apprehensions of Illegal Immigrants at All 

Locations in Each Southwest Border Patrol Sector in 

Fiscal Years 2001-2004 13 

Figure 3: IAFIS Fingerprint Screen and Reading Machine at the I-5 

San Clemente, California, Checkpoint 18 

Figure 4: VACIS Machine Examining a Vehicle at the I-15 Temecula, 

California, Checkpoint 19 

Figure 5: VACIS Monitor Display, I-5 Checkpoint, Temecula, 

California 20 

Figure 6: Vehicle Lift at the I-35 Checkpoint, North of Laredo, 

Texas 21 

Figure 7: Tactical Checkpoint at Sandia Creed Road, near 

Temecula, California 23 

Figure 8: Tucson Sector Nonpermanent Checkpoint at KP 42 on I19, Near Tubac, Arizona 29 

Figure 9: Apprehensions per Agent Work Year in the Tucson, San 

Diego, Laredo and McAllen Sectors, Fiscal Years 2001-

2004 41 

Figure 10: Road Infrastructure and Checkpoints in the San Diego 

Sector 56 

Figure 11: Permanent Checkpoint on I-5, South of San Clemente 57 

Figure 12: Aerial Photo of Checkpoint on I-5 South of San Clemente 58 

Figure 13: Tactical Checkpoint at Sandia Creek Road, near 

Temecula, California 62 

Figure 14: Road Infrastructure and Checkpoints in the Tucson 

Sector 65 

Figure 15: Tucson Sector Nonpermanent Checkpoint on I-19 near 

KP 42 67 

Figure 16: Nonpermanent Checkpoint on State Highway 85 near 

Ajo, Arizona 68 

Figure 17: Road Infrastructure and Checkpoints in the Laredo 

Sector 71 

Figure 18: Permanent Checkpoint North of Laredo, Texas, on I-35 72 
Page iii GAO-05-435 Border Patrol 

Figure 19: Permanent Checkpoint on State Highway 359 Near 

Hebbronville, Texas 74 

Figure 20: Aerial View of Highway 359 Checkpoint, Texas 75 

Figure 21: Architectural Drawing of the New I-35, Texas, 

Permanent Checkpoint 76 

Figure 22: Road Infrastructure and Checkpoints in the McAllen, 

Texas Sector 79 

Figure 23: Checkpoint Inspection Area, U.S. Highway 281, near 

Falfurrias, Texas 82 

Abbreviations 

ATV all-terrain vehicle 

CBP Customs and Border Protection 

DHS Department of Homeland Security 

FBI Federal Bureau of Investigation 

GPRA Government Performance and Results Act 

IAFIS Integrated Automated Fingerprint Identification System 

INS Immigration and Naturalization Service 

KP kilometer post 

PAL pre-enrolled access lane 

SR state route 

VACIS Vehicle and Cargo Inspection System 

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Page 1 GAO-05-435 Border Patrol 

July 22, 2005 

The Honorable Christopher Cox 

Chairman, Committee on Homeland Security 

House of Representatives 

The Honorable Harold Rogers 

Chairman, Subcommittee on Homeland Security 

Committee on Appropriations 

House of Representatives 

The Honorable Ken Calvert 

House of Representatives 

The Honorable Darrell Issa 

House of Representatives 

The Honorable Jim Kolbe 

House of Representatives 

The U.S. Border Patrol, now part of the Department of Homeland 

Security’s (DHS) U.S. Customs and Border Protection (CBP) agency, has 

as its primary mission the detection and apprehension of terrorists and 

their weapons, and a traditional mission of preventing illegal aliens and 

contraband smugglers from entering the United States, both at the land 

borders between ports of entry and inside the United States. According to 

the Border Patrol, its operations are intended to apprehend illegal 

entrants; deter potential illegal immigration, smuggling, or terrorism, 

through such apprehensions; and present a high-profile presence along our 

nation’s borders. On the southwest border, where the majority of illegal 

immigration into the United States occurs, the Border Patrol aims to 

accomplish its mission through what it describes as an integrated, 

multilayered border enforcement strategy. Along the border, between 

official ports of entry,1

 are the first two layers, consisting of a first called 

 1

Ports of entry are those official locations along the international border, as well as at U.S. 

international airports and seaports, where persons seeking entry into the United States go 

through passport control and customs inspection. The Office of Field Operations of U.S. 

Customs and Border Protection operates the nation’s 317 ports of entry. The Border Patrol 

is responsible for border security between the ports of entry. See U.S. Customs and Border 

Protection, Performance and Annual Report, Fiscal Year 2004, p.11 and p.12. 

United States Government Accountability Office

Washington, DC 20548 
Page 2 GAO-05-435 Border Patrol 

line watch and a second, called line patrol. Together, these are where the 

majority of the nation’s 10,800 U.S. Border Patrol agents are deployed, 

with agents positioned along the border line or somewhat farther back but 

still generally in visible proximity to the border, primarily in well-marked 

four-wheel-drive vehicles, to maintain a high profile to deter, turn back, or 

arrest anyone attempting to illegally enter the country. The line patrol 

layer consists of smaller contingents of agents deployed behind the line 

watch units to provide direct support of the line watch units. Given the 

1,950-mile U.S.-Mexican border, the Border Patrol states that it does not 

have the personnel to patrol all of it simultaneously and therefore 

allocates personnel based on a combination of intelligence information 

about potential threats from terrorists and contraband smugglers, as well 

as on the estimated volume of illegal entries. In addition, a third layer of 

enforcement is composed of interior traffic checkpoints at which Border 

Patrol agents monitor and stop vehicles at checkpoints—both permanent 

and tactical (temporary)—on major U.S. highways and secondary roads 

that are generally 25 to 75 miles inland from the border. This permits them 

to be far enough inland to detect and apprehend potential terrorists and 

illegal aliens attempting to travel farther into the interior of the United 

States after evading detection at the border, but that are close enough to 

the border to potentially control access to major population centers. The 

permanent interior traffic checkpoints are locations that generally have 

large, tollbooth-like structures at which agents may stop vehicles for visual 

inspection, and to decide whether a more thorough inspection of the 

vehicle and its occupants is warranted. There are 33 such permanent 

interior traffic checkpoints in the southwest border states, and one in 

northern New York state. The tactical checkpoints, the number and 

location of which may change daily, respond to intelligence on changes in 

illegal activity routes and generally consist of a few vehicles, portable 

water tanks, traffic cones and signs, and a mobile trailer. The permanent 

checkpoints are intended to apprehend illegal entrants and contraband, 

and through the perception of potential apprehension, to deter illegal 

entrants from using major highways or roads. Permanent checkpoints 

have supporting infrastructure and procedures intended to reduce the 

ability of illegal entrants from circumventing the checkpoints; these 

include remote video surveillance, electronic sensors, and agent patrols. 

With permanent checkpoints on major routes, the Border Patrol seeks to 

cause illegal entrants to use less traveled secondary roads on which they 

are more visible, and where less traffic permits stopping a much higher 

percentage of transiting vehicles than on interstates, as well as questioning 

vehicle occupants, adding to the costs of smuggling or transit time, as well 

as to the likelihood of being detected and apprehended. 
Page 3 GAO-05-435 Border Patrol 

In addition to the use of agents to maintain surveillance along the border 

between official ports of entry, and inland at the interior checkpoints, the 

Border Patrol carries out its mission by responding to electronic sensor 

alarms and aircraft sightings, interpreting and following tracks, and 

patrolling in a wide variety of modes, including using horses, helicopters, 

small aircraft, patrol boats, off-road all-terrain vehicles (ATVs), and 

mountain bikes. These agents and their modes of operation are deployed 

as an integrated strategy in which agents can be shifted daily among line 

watch, line patrol, and interior checkpoint operations, as well as other 

duties, to respond to changes detected in the tactics and routes of those 

attempting to enter the United States illegally. 

With the continued influx of illegal immigration along the U.S.-Mexican 

border, contraband smuggling, and ongoing threats of terrorism and 

weapons of mass destruction potentially entering the country, you 

expressed interest about the operations of the Border Patrol’s permanent 

and tactical traffic checkpoints in the southwest border states within the 

context of overall border security. To address your interests, this report 

focuses on 

• how the Border Patrol uses permanent and tactical checkpoints in the 

southwest border states as part of its strategy to detect and apprehend 

potential terrorists, illegal immigrants, and contraband smugglers, and 

to deter potential future violators through the likelihood of 

apprehension, as well as to cause them to avoid permanent 

checkpoints on major routes and take less traveled secondary roads on 

which they would more likely be apprehended at tactical checkpoints; 

• what is known about the costs and benefits of interior traffic 

checkpoint operations, including their impact on local law enforcement 

and local communities, as well as in terms of the amount of contraband 

seized and illegal entrants and potential terrorists apprehended; and 

• what data and performance measures are used by the Border Patrol to 

evaluate interior traffic checkpoint operations, in terms of their overall 

effectiveness in meeting agency mission goals and how might Border 

Patrol data be used to develop additional measures of productivity and 

effectiveness. 

However, this report does not address some of the larger issues 

surrounding illegal immigration into the United States, such as the 

disparities in average daily wages between Mexico and the United States, 

and the incentives created by these disparities for illegal immigration, as 
Page 4 GAO-05-435 Border Patrol 

well as the difficulties of neutralizing such disparities through work site 

enforcement. We have elsewhere addressed some of these issues.2

 In 

addition, although deterring illegal immigration through the likelihood of 

detection and apprehension is a goal of the Border Patrol, we did not 

attempt to measure the deterrent effect of the Border Patrol’s operations, 

as this would have required, among other things, opinion surveys of 

Mexican citizens and potential contraband smugglers. 

To address these objectives, we reviewed Border Patrol documents, 

reports, manuals, and guidance concerning border strategy and 

checkpoint operations, as well as CBP’s annual performance reports.3

 We 

interviewed Border Patrol officials at CBP headquarters in Washington, 

DC. We also interviewed Border Patrol sector headquarter officials and 

observed operations at checkpoints in the San Diego, California; Tucson, 

Arizona; Laredo, Texas; and McAllen, Texas, Border Patrol sectors. (The 

other 5 southwest border sectors are El Centro, California; Yuma, Arizona; 

El Paso, Texas; Marfa, Texas; and Del Rio, Texas. In addition to these 9 

southwest sectors, the remainder of the country is divided into 11 

additional sectors by the Border Patrol.) 

The 4 sectors we visited were selected to provide a substantial range in the 

size and types of interior checkpoint operations; estimated volume of 

illegal annual immigration; volume of vehicular traffic transiting 

checkpoints; topography and density of road networks; presence or 

absence of large urban areas on or near the border, on both the U.S. and 

Mexican sides; and types of checkpoints (permanent and tactical).4

 Since 

we were unable to observe all operating conditions at all times, the 

conditions we describe are therefore based on available documentation 

and observations from our site visits only. (See app. I for further 

discussion of the range of conditions among these sectors.) 

 2

See, for example, GAO, Department of Homeland Security: Addressing Management 

Challenges That Face Immigration Enforcement Agencies, GAO-05-664T (Washington, 

D.C.: May 5, 2005). See also GAO, Immigration Enforcement: DHS Has Incorporated 

Immigration Enforcement Objectives and Is Addressing Future Planning Requirements, 

GAO-05-66 (Washington, D.C.: Oct. 8, 2004). 

3

For example, see U.S. Customs and Border Protection, Performance and Annual Report, 

Fiscal Year 2004, and the same for fiscal year 2003. 

4

The Tucson sector has checkpoints that are neither permanent nor tactical as operated by 

the Border Patrol in other sectors, because of varying legislative restrictions that started in 

fiscal year 1999. These differences are explained in greater detail below. 
Page 5 GAO-05-435 Border Patrol 

We also interviewed local law enforcement, business, and community 

leaders in communities near interior traffic checkpoints with regard to the 

impact of the checkpoints. Because these places were selected using a 

nonprobabilistic method, the results from our site visits cannot be 

generalized to other locations and checkpoints. To assess the reliability of 

the Border Patrol’s data, we talked with agency officials at both 

Washington, D.C., headquarters and at some Border Patrol stations in the 

field about data quality control procedures, including methods by which 

data are checked and reviewed internally for accuracy and consistency. 

We determined that the Border Patrol utilizes processes and checks that 

provide reasonable assurance that the data recorded on apprehensions, 

work hours, and contraband seizures are accurate and sufficiently reliable 

for the purposes of this report. We conducted our work from September 

2004 to May 2005 in accordance with generally accepted government 

auditing standards. Additional details on our scope and methodology can 

be found in appendix I. Detailed information on the four Border Patrol 

sectors that we visited can be found in appendixes II through V. 

Interior traffic checkpoints function as part of the Border Patrol’s 

multilayered enforcement strategy, to increase the likelihood of detecting 

potential terrorists, illegal immigrants, and smugglers who have crossed 

the border and evaded patrols at and near the border. By increasing the 

possibility of apprehension, the Border Patrol seeks to enhance national 

security and to enforce existing immigration and contraband smuggling 

laws, thereby deterring potential future illegal entrants from crossing the 

border. The Border Patrol operates 33 permanent interior traffic 

checkpoints in 8 of its 9 sectors along the southwest border. In all sectors 

except Tucson, permanent checkpoints are supported by additional 

tactical checkpoints. Permanent checkpoints may operate 24 hours a day, 

7 days a week, with their infrastructure supporting access to computers 

and technology, buildings with detention facilities, shade and water for 

canines, paved shoulder areas with sufficient space for vehicle lift 

equipment essential to inspecting underneath vehicles, as well as the 

space required for gamma-ray machines that examine other vehicles. The 

number and location of tactical checkpoints can change on a daily basis, 

depending on a combination of available resources and intelligence about 

illegal entrants’ routes, which the Border Patrol uses to decide where to 

set up tactical checkpoints. 

In the Tucson sector, however, Congress has prohibited the construction 

of checkpoints since fiscal year 1999. Since the sector had no permanent 

checkpoints prior to the prohibition—and used portable equipment to 

Results in Brief 
Page 6 GAO-05-435 Border Patrol 

establish checkpoints that moved infrequently, but that also had no 

permanent structures5

—the effect of the legislative language was to 

prevent construction of permanent checkpoints. Moreover, starting in 

June 2002, at the instruction of congressional staff, and beginning in fiscal 

year 2003 to comply with legislative language, the Border Patrol has been 

relocating or closing checkpoints in the Tucson sector on a regular basis—

at least once every 7 days in the last quarter of fiscal year 2002, and in 

fiscal years 2003 and 2004. In fiscal year 2005, the legislative language was 

less restrictive, requiring relocating Tucson sector checkpoints “at least an 

average of once every14 days.” The Border Patrol has implemented that 

language by keeping one checkpoint in the sector open for 14 days, closed 

for 8 hours, and then reopened for 14 days, while other checkpoints are 

maintained on varying schedules that the Patrol believes to be in 

conformity with the law. The result of these legislative restrictions in the 

Tucson sector has been that the Border Patrol operates what we refer to 

as nonpermanent checkpoints that are hybrids of permanent and tactical 

but that lack the logistical, communication, and other capabilities 

provided by the physical infrastructure of permanent checkpoints or the 

flexibility of tactical checkpoints. In the Tucson sector, according to 

Border Patrol officials, the lack of permanent infrastructure, in 

combination with the mandated relocation on a regular basis, results in 

closure at 3 of 6 sector checkpoints because of an inability to find an 

alternate location that meets safety requirements for adequate shoulder 

areas and advance notice to vehicles that they are approaching a 

checkpoint. To support these nonpermanent checkpoints, the Tucson 

sector operates tactical checkpoints periodically, as occurs in other 

sectors with permanent checkpoints. 

Some benefits of interior traffic checkpoints are more easily quantified 

than others, but a lack of data makes it difficult to estimate both the direct 

costs of interior traffic checkpoints, resulting from labor and overhead, or 

indirect costs, such as delays caused to commuters or commercial 

shippers. Quantifiable benefit data include such measures as 

apprehensions of persons in violation of immigration laws and the 

detection and seizure of illegal drugs and other contraband. For example, 

in fiscal year 2004, interior checkpoints in the 9 southwest sectors, with 

 5

According to the Border Patrol, it used a combination of roving patrols and temporary 

checkpoints that remained at the same location for long periods but that did not have 

permanent infrastructure. The Border Patrol stated that it was not until the late 1990s that 

traffic volume and illegal immigration reached a level where it felt that permanent 

checkpoints were necessary to address the sector’s needs. 
Page 7 GAO-05-435 Border Patrol 

about 10 percent of total Border Patrol personnel in those sectors assigned 

to these checkpoints, accounted for the detection and apprehension of 

over 96,000 illegal aliens, about 8 percent of the total apprehensions by the 

Border Patrol that year. In addition, interior traffic checkpoint operations 

in the 9 southwest sectors seized 418,102 pounds of marijuana and 10,853 

pounds of cocaine in fiscal year 2004, or about 31 percent of the marijuana 

and about 74 percent of the cocaine seized nationally by the Border Patrol. 

Less quantifiable were the benefits cited by most local law enforcement, 

business, and community leaders we interviewed, who spoke positively of 

reductions in crime and vandalism by smugglers and illegal aliens. As for 

the cost of checkpoint operations, the Border Patrol did not maintain the 

costs of checkpoints, either individually or collectively, in readily 

accessible databases.6

 Data were also not available on some indirect 

costs, such as those associated with traffic delays and congestion. For 

example, professional organizations that monitor traffic, such as the 

Automobile Club of Southern California, American Trucking Associations, 

the California Highway Patrol, and the California Department of 

Transportation, do not report problems for commuters, commercial 

shippers, or tourists resulting from interior checkpoints on major traffic 

arteries in the sectors we visited. Literature searches and information 

requests did not produce data, studies, or reports on traffic, business 

costs, or crime rates that reported or systematically analyzed either 

benefits or adverse effects. Traffic congestion and backups do occur at 

some of the checkpoints on major highways, but at several we visited we 

observed that traffic is monitored, with operations ceasing and traffic 

“flushed” to normal flows whenever agents determined wait time to be 

excessive. For example, the Temecula, California, I-15 checkpoint 

guidance states that agents should not permit a backup exceeding a 

certain approximate distance and certain approximate number of minutes’ 

wait.7

 The costs to commuters and commercial traffic that may occur 

from delays at the checkpoints could not be calculated, since no data are 

available on the number of commuters delayed annually at the 33 

permanent southwest checkpoints, the length of the delays, the salaries of 

those delayed, or economic losses to commerce that may have resulted 

from traffic delays. Furthermore, costs are difficult to calculate since the 

 6

Cost data we obtained on interior checkpoints had to be collected through data requests to 

each sector, and were not available for permanent versus tactical checkpoints. 

7

Because of the sensitivity of some operational guidance, the Border Patrol requested that 

we not provide precise numbers. 
Page 8 GAO-05-435 Border Patrol 

Border Patrol does not routinely maintain data on the costs of operating 

checkpoints. 

Performance measures of how well a government agency carries out its 

mission are essential to annual assessment and improvement, not least 

because such measures help management identify problems and allocate 

resources to solve them. However, we found that the Border Patrol does 

not systematically evaluate the effectiveness of interior checkpoint 

operations. CBP annually prepares and sends to the Congress a 

Performance and Annual Report. In these reports, CBP uses traditional 

measures of law enforcement performance—including numbers of 

apprehensions and amount and type of contraband seized—to report on 

Border Patrol performance. In the two most recent annual reports, no 

data or analysis are cited with regard to the performance of interior 

checkpoints. These reports would be more useful to CBP and the 

Congress if they included additional measures to compare interior 

checkpoints’ effectiveness with that of line watch and line patrol 

operations. This could help to ascertain whether the personnel and 

equipment resources allocated to differing layers in the multilayered 

strategy are right- sized. Traditional measures do not take into account 

inputs such as labor and overhead costs, thereby making it difficult to 

determine if one sector, or type of checkpoint, is more cost effective than 

others. For example, knowing that more illegal immigrants are 

apprehended in one sector than in another does not tell managers if that is 

a result of having more agents on the line or at more interior checkpoints 

in that sector compared with others. Alternatively, it does not provide 

information on whether the apparent success in apprehensions is more a 

function of a large volume of attempted entries than better agent work or 

positioning of checkpoints, relative to other sectors. 

Using available data, we developed two performance measures to 

supplement the traditional law enforcement measures used by the Border 

Patrol. These two measures alone do not exhaust the potential ways in 

which checkpoint operations could be assessed, and should not be 

considered in isolation from the broader context of the multilayered 

strategy, as well other factors that could affect checkpoint and line 

watch/line patrol operations, such as the volume of illegal immigration 

into a sector. With these caveats in mind, we compared data on the 

performance of interior checkpoints in the Tucson sector with those in the 

three other sectors we visited in terms of apprehensions per agent work 
Page 9 GAO-05-435 Border Patrol 

year, and costs per apprehension, based on an average work year cost.8 

We found that while checkpoint performance, as measured by 

apprehensions per agent work year, varied among sectors and by fiscal 

years, a substantial drop started in the Tucson sector in fiscal year 2002, 

when the Border Patrol began to routinely relocate or close its 

checkpoints every 7 days, starting in June 2002, with another substantial 

drop in fiscal year 2003, when statutory language went into effect. In 

contrast, comparable decreases in checkpoint performance data did not 

occur in the 3 other sectors we visited, which were not required to 

relocate or close checkpoints every 7 days in the last quarter of fiscal year 

2002, or in fiscal years 2003 and 2004 (14 days on average in fiscal year 

2005). At the same time, it is important to recognize that there may be 

other factors that affected this performance measure that we were unable 

to measure or of which we were unaware. While the two performance 

measures we developed are some of many possibilities to assess 

effectiveness, Border Patrol officials told us that they found the two 

measures potentially useful as tools for making allocation decisions, in 

conjunction with other data and information. 

To better gauge the effects of border control efforts, and in order to more 

effectively manage and allocate resources, we are recommending that the 

Commissioner of Customs and Border Protection develop performance 

measures for the Border Patrol in addition to its traditional ones, of the 

productivity and effectiveness of interior checkpoints. We are also 

recommending that the Commissioner include in CBP’s Performance and 

Annual Report data and analysis provided by the additional performance 

measures on the performance of interior checkpoints and what might be 

done to improve their effectiveness. In commenting on a draft of this 

report, DHS agreed with the recommendations and stated that CBP is 

taking steps to implement them. 

 8

Work years are total hours charged by agents to work at a given location, divided by 2080 

(a 40-hour week times 52 weeks). Costs of apprehensions per agent work year were 

calculated by dividing the average nationwide fiscal year 2004 salary of a Border Patrol 

agent ($53,000) by the number of apprehensions per work year reported for checkpoints, 

such as 191 apprehensions per work year in fiscal year 2004 at interior checkpoints in the 

San Diego sector. In this instance, $53,000 divided by 191 produced a cost per 

apprehension of $277. 
Page 10 GAO-05-435 Border Patrol 

U.S. Customs and Border Protection, a component of the Department of 

Homeland Security, has the primary responsibility for securing the 

nation’s borders. The U.S. Border Patrol is the uniformed enforcement 

division of CBP responsible for border security between designated 

official ports of entry into the country. According to the Border Patrol, its 

priority mission since the terrorist attacks of September 11, 2001, has been 

to prevent terrorists and terrorist weapons from entering the United States 

between official ports of entry. In addition, the Border Patrol has a 

traditional mission of preventing illegal aliens, smugglers, narcotics, and 

other contraband from entering the country, as these activities directly 

affect the safety and security of the United States. Border Patrol agents 

generally report to Border Patrol stations and substations in each of these 

sectors at the start and end of their workdays; these stations function 

much as police stations do for police personnel around the country. The 

number of stations and substations varies widely by sector.9

The Border Patrol’s fiscal year 2005 budget was about $1.4 billion. As of 

March 2005, the Border Patrol had 10,817 agents nationwide; 6,129 (57 

percent) were located in the 9 Border Patrol sectors along the southwest 

border. About 10 percent of the Border Patrol’s agents nationwide are 

assigned to interior traffic checkpoints in the southwest border sectors, 

according to the Border Patrol. 

Permanent and tactical interior traffic checkpoints are generally located 

on major and secondary roads, usually 25 to 75 miles inland from the 

border. These interior checkpoint locations are chosen by the Border 

Patrol to maximize the likelihood that illegal entrants who have managed 

to evade border defenses and patrols will have to pass through the 

checkpoints in order to get to major U.S. population centers. Although 

tactical checkpoints are mobile and may move daily or weekly, as needed, 

they must provide adequate advance notice to motorists that a checkpoint 

has been set up and is in operation. This is typically done by using orange 

traffic cones and large, visible signs positioned in advance of the 

checkpoint location. Permanent checkpoints, by virtue of their 

 9

According to the Border Patrol, Border Patrol stations are responsible for a specific 

geographic area within a sector. Substations are responsible for a geographic area within a 

station’s area of responsibility. Stations are composed of a minimum of one patrol-agentin-charge, one or more supervisory Border Patrol agents, numerous Border Patrol agents 

and support staff and associated equipment required to carry out their duties. Substations 

report to the parent station. Stations, in turn, report to the sector chief patrol agent. 

Background 
Page 11 GAO-05-435 Border Patrol 

permanence and large traffic signs, meet these criteria for advance notice 

and visibility. 

Figure 1 shows the topography, interstate highways, and some major 

secondary roads along the southwest border. 

Figure 1: Topography and Road Systems along the Southwest Border 

Note: The U.S.-Mexican border is denoted by the black line that starts at the far left in San Diego, 

California, and that moves to the far right, ending at Brownsville, Texas. 

The legacy Immigration and Naturalization Service (INS) Border Patrol 

began implementing a strategy called Operation Hold-the-Line in 1993, to 

incrementally increase control of the Southwest border in four phases by 

Gulf of

Mexico

Pacific

Ocean

8 8

15

19

20

Major interstate road

State road

Desert areas

Mountain ranges

Source: GAO.

37

5

California Arizona New Mexico Texas Oklahoma

35

35

25

10

10

10

10

10

98

2

2

191

2

2

45

2

90

57

85

59

77

16

85

86

8

2

67 377 277

281

15

77

Mexicali

Mexico

Del Rio

Laredo

Deming

Tucson

Douglas

Brownsville

Monterrey

El Paso

Calexico

Nogales

San

 Antonio

San Diego

Eagle

Pass

Marfa

Yuma

El Centro

McAllen

Presidio

Colorado

River

Rio Grande

River

Rio Grande

River

Hermosillo

15

45

1

1

5

49

49
Page 12 GAO-05-435 Border Patrol 

making it so difficult and costly for aliens to attempt illegal entry that 

fewer individuals would try.10 The four-phased approach involved adding 

resources along the Southwest border, starting with the areas that had the 

highest known levels of illegal alien activity, which at that time were the 

San Diego, California; El Paso, Texas; and McAllen, Texas, regions.11

Although INS accomplished its goal of shifting illegal alien traffic away 

from these areas, the shift was achieved at a cost to both illegal aliens and 

INS.12 In particular, rather than being deterred from attempting some 

illegal entry, many aliens have instead risked injury and death by trying to 

cross mountains, deserts, and rivers, primarily in Arizona and in particular 

in the Tucson sector. These conditions, which the Border Patrol said 

continue to the present day, prompted INS and now CBP to warn aliens 

about the dangers of crossing illegally, as well as to establish search-andrescue units. 

In effect, and contrary to the expectations of INS, the strategy led to a 

significant increase in illegal immigration through the Tucson sector, 

despite its topography and climate, as indirectly measured by total 

apprehensions, which increased nearly sevenfold in this sector over the 

period of fiscal years 1993 to 2000. In contrast, during the same period, 

total apprehensions for the eight other southwest sectors combined 

decreased by about 28 percent. The largest single decrease was in the San 

Diego sector, where apprehensions fell by almost three-fourths over 1993- 

2000. 

Nationwide, Border Patrol apprehensions at all locations (including on the 

border, near the border, and at interior checkpoints) of illegal aliens over 

the last 4 years have varied from about 1.3 million in fiscal year 2001, to 

955,000 in fiscal year 2002, 931,000 in fiscal year 2003, and over 1.1 million 

in fiscal year 2004. Figure 2 shows the total annual apprehensions of illegal 

immigrants at all locations in each of the 9 southwest Border Patrol 

sectors reported for fiscal years 2001 to 2004. 

 10U.S. Customs and Border Protection, Performance and Annual Report, Fiscal Year 2003, 

p. 43. 

11U.S. Customs and Border Protection, Performance and Annual Report, Fiscal Year 2003, 

p. 42 and p. 43. 

12GAO, INS’ Southwest Border Strategy: Resource and Impact Issues Remain after Seven 

Years, GAO-01-842 (Washington, D.C.: Aug. 2, 2001).
Page 13 GAO-05-435 Border Patrol 

Figure 2: Total Apprehensions of Illegal Immigrants at All Locations in Each Southwest Border Patrol Sector in Fiscal Years 

2001-2004 

As shown, the Tucson sector has had the largest numbers of 

apprehensions since fiscal year 2001, which Border Patrol officials 

attribute in part to the legacy INS’s strategy to deter illegal entry between 

the official ports of entry in the sectors that had the highest estimated 

illegal immigration in the early and mid-1990s, the San Diego, California, 

and the Texas sectors of El Paso and McAllen.13 It is apparent that in 

recent years far more apprehensions of illegal aliens have occurred in the 

Tucson sector than in the 8 other sectors. 

When establishing checkpoints, the Border Patrol must take into account 

court decisions ruling on the parameters of immigration officers’ authority 

 13U.S. Customs and Border Protection, Performance and Annual Report, Fiscal Year 2003, 

p. 43. 

0

100,000

200,000

300,000

400,000

500,000

600,000

Apprehensions

Source: GAO analysis of CBP data.

Sector

Fiscal year 2001

Fiscal year 2002

Fiscal year 2003

Fiscal year 2004

San Diego,

Calif.

El Centro,

Calif.

Yuma,

Ariz.

Tucson,

Ariz.

El Paso,

Tex.

Marfa,

Tex.

Del Rio,

Tex.

Laredo,

Tex.

McAllen,

Tex.
Page 14 GAO-05-435 Border Patrol 

to conduct inquiries concerning illegal aliens. The legal authority of 

immigration officials to establish permanent checkpoints and stop vehicles 

transiting through them has been confirmed by the Supreme Court in 

United States v. Martinez-Fuerte.

14 The Supreme Court ruled that 

government officials may stop vehicles at permanent interior checkpoints 

for brief questioning of the driver and passengers without reasonable 

suspicion. The Court held that it was constitutional for the Border Patrol, 

after routinely stopping or slowing automobiles at a permanent 

checkpoint, to refer motorists selectively to a secondary inspection area 

for questions about citizenship and immigration status on the basis of 

criteria that would not sustain a roving patrol stop.15 The Court 

determined that the constitutional interests of motorists at these 

checkpoints were not violated, for a number of reasons. It found that the 

checkpoints, with flashing lights and warning signs, provided advance 

notice to motorists of an official roadblock that was applicable to all 

motorists.16 Motorists were not taken by surprise, as they knew, or could 

find out, the location of the checkpoints. Furthermore, the Court 

concluded that the regular manner in which established checkpoints were 

operated was visible evidence that the stops were duly authorized.17

An organization that specializes in immigration issues has estimated that 

the number of people who have successfully entered the United States 

illegally has averaged roughly half a million per year since 1990 and that 

the number of illegal aliens residing in the United States has grown in 

recent years from about 8.4 million in April 2000 to about 11 million in 

March 2005.18

 14428 U.S. 543 (1976). 

15A roving patrol stop is a stop by an agent who patrols in a vehicle but who is not assigned 

to a particular location. 

16One of the checkpoints was functional only about 70 percent of the time because of 

personnel shortages. 428 U.S. 543, 554. 

17There are a number of court decisions concerning the use of permanent and temporary 

checkpoints, as well as roving patrols. In United States v. Brignoni-Ponce, 422 U.S. 873 

(1975), the Supreme Court ruled that under the Fourth Amendment, except at the border or 

its functional equivalents, officers on roving patrols may stop vehicles only if “specific 

articulable facts” give rise to suspicion. 

18Pew Hispanic Center, Estimates of the Size and Characteristics of the Undocumented 

Population, February 21, 2005. Given that these estimates are provided for background 

purposes, we did not assess their reliability. 
Page 15 GAO-05-435 Border Patrol 

The Border Patrol uses permanent and tactical checkpoints in 8 of its 9 

southwest sectors as part of a multilayered enforcement strategy to deter 

and defend against potential terrorists and their weapons, contraband 

smugglers, and persons who have entered the country illegally.19

Corresponding to their different roles in the Border Patrol’s enforcement 

strategy, permanent and tactical checkpoints have different capabilities. 

Permanent checkpoints have the advantage of physical infrastructure, 

which provides a wide range of logistical, communication, suspect 

questioning and detention, and equipment deployment and storage 

capabilities, as well as adequate shade and cages for canines. Tactical 

checkpoints have the advantage of mobility, which gives the Border Patrol 

the capability to respond quickly to emerging trends, intelligence, or 

national security threats. According to the Border Patrol, permanent 

checkpoints are most effective when supplemented by tactical 

checkpoints, which are generally used on secondary roads to cut off 

access to those seeking to evade permanent checkpoints on major 

arteries. 

This is not the case in the Tucson sector, where legislative language has 

prohibited the construction of checkpoints since fiscal year 1999. 

Moreover, starting in mid-2002, and through fiscal year 2004, the Border 

Patrol relocated or closed checkpoints in the Tucson sector on a regular 

basis, such as at least once every 7 days. The result has been a sector of 

nonpermanent checkpoints that lack the advantages of either permanent 

or tactical checkpoints, and which the Border Patrol states have degraded 

the Border Patrol’s ability to fulfill its mission in the Tucson sector. 

The Border Patrol uses interior traffic checkpoints as a third layer of 

defense and deterrence against potential terrorists and their weapons, 

contraband smugglers, and persons who have entered the country illegally. 

According to the Border Patrol, permanent and tactical checkpoints are 

part of an integrated, multilayered enforcement strategy intended to 

achieve two key law enforcement objectives: (1) to increase the likelihood 

of detection and apprehension of illegal entrants of all types, and thereby 

to deter other potential illegal entrants from attempting to enter the 

country, who might otherwise believe that successfully crossing the 

border would mean that there were no further barriers to them, and (2) to 

 19As noted previously, varying legislative restrictions since fiscal year 1999 on the Tucson 

sector have affected funding and operations of its checkpoints. 

Permanent and 

Tactical Checkpoints 

Have Different but 

Complementary Roles 

in the Border Patrol 

Strategy 

Permanent and Tactical 

Checkpoints Each Have a 

Role in the Border 

Enforcement Strategy 
Page 16 GAO-05-435 Border Patrol 

deter illegal entrants from transiting through permanent checkpoints on 

major roadways, through fear of detection, and thereby to cause them to 

use less traveled secondary roads on which the Border Patrol is able to 

stop all or almost all vehicles (because of much lower traffic volume), 

making illegal entrants more visible and easier to detect and apprehend.20

Procedures at both permanent and tactical checkpoints involve slowing or 

stopping traffic as vehicles proceed through the checkpoint. As traffic 

slows, Border Patrol agents use visual cues and canines trained to locate 

drugs and hidden persons to determine whether to wave the vehicle 

through, or stop the vehicle, question the occupant(s), and determine 

whether a more thorough secondary inspection is required. 

Permanent checkpoints are placed at locations that are intended to 

maximize the chances to detect illegal immigrants and smugglers who 

have crossed the border illegally and who are seeking to reach large 

population centers, such as Los Angeles, California, or Phoenix, Arizona. 

Where possible, according to the Border Patrol, permanent checkpoints 

are placed after several highways or roads join, so that anyone intending 

to exit the area into the interior of the country must transit them. 

Permanent checkpoints’ physical infrastructure gives them different 

capabilities than tactical checkpoints. For example, permanent 

checkpoints facilities are equipped with technology and computers 

connected to national law enforcement databases to help identify 

suspects, research criminal histories, and cross check terrorist watch lists. 

They also offer greater physical safety to those working at them, by virtue 

of better signage, lighting, and larger shoulder areas to stand out of the 

way of traffic, and many of them are paved and have protective concrete 

barriers. In addition, permanent checkpoints have supporting 

infrastructure and procedures intended to reduce the ability of illegal 

entrants from circumventing the checkpoints. These include remote video 

surveillance, electronic sensors, and agent patrols in the vicinity of the 

checkpoints. 

 20The Border Patrol refers to both these intended effects as deterrence—that is, deterrence 

of illegal entry into the United States from Mexico, and deterrence of illegal entrants from 

using high-volume highways where they can more easily blend into thousands of vehicles 

transiting permanent checkpoints. We have chosen to use this terminology as the Border 

Patrol uses it. 

Role of Permanent Checkpoints 
Page 17 GAO-05-435 Border Patrol 

Among the resources that are generally found at permanent checkpoints 

are: 

• Computers hardwired into national law enforcement databases, such 

as the Federal Bureau of Investigation’s (FBI) Integrated Automated 

Fingerprint Identification System (IAFIS) system, to provide identity 

checks. Figure 3 shows a fingerprint reading machine at a permanent 

checkpoint as it scans a fingerprint and then transmits the information 

to a centralized database via high-speed communications primarily 

available through a hardwired, secure line.21

 21According to the Border Patrol, it is seeking to field a vehicle that carries equipment 

capable of securely transmitting data. However, the high cost of the vehicles, at about 

$114,000 each, and technological difficulties have slowed this program. In addition to the 

initial purchase cost, there is also a recurring expense for satellite time that is estimated at 

$12,000 per month per link. In comparison, the average cost of installing permanent hardline database access in a facility is $30,000, with an estimated recurring monthly expense of 

$3,000 for T-1 line access. 
Page 18 GAO-05-435 Border Patrol 

Figure 3: IAFIS Fingerprint Screen (at left) and Reading Machine (at right) at the I-5 

San Clemente, California, Checkpoint 

• Vehicle and Cargo Inspection System (VACIS) machines that use gammaray technology to examine the contents of vehicles, including trucks. As 

figure 4 shows, this equipment is substantial in size and requires an offroad area sufficient to permit its safe operation without interfering with 

traffic flow. The VACIS truck moves its arm over the subject vehicle, 

producing a color display of the interior that is visible on a color monitor 

inside the truck. Figure 5 shows how a car appeared on the monitor; the 

actual display is in color. 

Source: GAO.
Page 19 GAO-05-435 Border Patrol 

Figure 4: VACIS Machine Examining a Vehicle at the I-15 Temecula, California, 

Checkpoint 

Source: GAO.
Page 20 GAO-05-435 Border Patrol 

Figure 5: VACIS Monitor Display, I-5 Checkpoint, Temecula, California 

• Electrical and water utilities 

• Permanent tollbooth-like structures that provide cover from the 

weather, including shade for agents and canines 

• Buildings with room for processing and detention of persons suspected 

of smuggling or other illegal activity 

• Permanent, large communication towers that permit radio 

communication to other Border Patrol facilities and national law 

enforcement authorities 

• Permanent lighting for night and poor weather conditions 

• Vehicle lifts to raise vehicles to inspect under them, and the area 

required for the lifts, as shown in figure 6. 

Source: GAO.
Page 21 GAO-05-435 Border Patrol 

Figure 6: Vehicle Lift at the I-35 Checkpoint, North of Laredo, Texas 

Tactical checkpoints are intended to supplement permanent ones by 

monitoring and inspecting traffic on secondary roads that can be used to 

evade the permanent checkpoints. For example, the Temecula permanent 

checkpoint in the San Diego sector maintains up to eight tactical 

checkpoints to inspect vehicles traveling on back roads in the hills around 

the permanent checkpoint on I-15. Tactical checkpoints are intended to 

be mobile and set up for short-term use only. They are relocated by the 

Border Patrol in order to respond to intelligence on changing patterns of 

contraband smuggling and routes being used by illegal aliens. According 

to the Border Patrol, the combination of permanent and supplemental 

tactical checkpoints is intended to both detect persons who have entered 

the country illegally and to increase the chances of detecting and 

apprehending contraband smugglers and illegal aliens who seek to avoid 

permanent checkpoints and instead use less traveled routes. On these less 

traveled routes, with comparatively low traffic volume of as little as a few 

Role of Tactical Checkpoints 

Source: GAO.
Page 22 GAO-05-435 Border Patrol 

hundred vehicles daily, the Border Patrol is able to stop every car and 

closely observe the occupants, as well as question them.22 This increases 

the likelihood of detecting illegal entrants, while on heavily traveled 

highways, only a small percentage of vehicles can be subjected to this 

level of inspection, in order to avoid creating long traffic delays. 

In contrast to the resources that are typically deployed at permanent 

checkpoints, tactical ones, by virtue of their mobility, do not have large 

fixed facilities or hardwired communications. They do, however, offer the 

element of flexibility, by virtue of their mobility. Tactical checkpoints 

generally consist of a few Border Patrol vehicles, used by agents to drive 

to the location; orange cones to slow down and direct traffic; portable 

water supply; a cage for canines (if deployed with the checkpoint); 

portable rest facilities; and warning signs. Some may also have portable 

lighting, if operated at dusk or night. If persons are detained at a tactical 

checkpoint, some of the agents must leave the checkpoint to transport 

them back to a Border Patrol station for positive identification. Our 

observations of tactical checkpoints showed that most equipment has to 

be towed or carried to the checkpoint for it to operate, and then has to be 

removed when it relocates. According to the Border Patrol, this increases 

wear and tear on the equipment and absorbs time to hitch up, tow, set up, 

dismantle, and tow the equipment back to a Border Patrol station or to an 

alternate tactical checkpoint. Figure 7 shows a tactical checkpoint on 

Sandia Creek road, in a rural area near Temecula, California, that was used 

to supplement the permanent checkpoint on I-15. 

 22For example, a daily average of 122,000 vehicles go through the I-15 checkpoint near 

Temecula, California, while Border Patrol data for the 8 tactical checkpoints that support 

the permanent one on I-15 show average daily volume ranging from about 100 to about 800 

vehicles. 
Page 23 GAO-05-435 Border Patrol 

Figure 7: Tactical Checkpoint at Sandia Creek Road, near Temecula, California 

While the changing locations of tactical checkpoints would appear to offer 

the potential element of surprise, we were told by the Border Patrol that 

the smugglers of aliens and contraband could use cell phones and 

communications networks to alert confederates of the presence of 

checkpoints within minutes of their being relocated. The Border Patrol 

provided us with information that confirmed that smugglers of aliens and 

contraband observed some checkpoints and reported on their activities to 

their confederates. According to the Border Patrol, smugglers know 

within minutes about the closure of a checkpoint. 

Source: GAO.
Page 24 GAO-05-435 Border Patrol 

For fiscal years 1999-2004, annual appropriations acts made no funds 

“available for the site acquisition, design, or construction” of any Border 

Patrol checkpoint in the Tucson sector.23 Since the Tucson sector had no 

permanent checkpoints at the time the prohibition was first imposed, the 

effect of this restriction was that no permanent checkpoints could be 

planned or constructed in this sector. According to the Border Patrol, it 

used a combination of roving patrols and temporary checkpoints in the 

sector that remained at the same location for long periods but did not have 

permanent infrastructure. This arrangement was adequate, the Border 

Patrol stated, until the late 1990s, when the volume of illegal entrants into 

the sector increased substantially as its overall strategy to greatly 

reinforce the border in urbanized areas took effect in San Diego, 

California; El Paso, Texas; and McAllen, Texas. 

The fiscal year 2003 and 2004 Appropriations Acts also added a provision 

requiring that the checkpoints in the Tucson sector be relocated “at least 

once every 7 days in a manner designed to prevent persons subject to 

inspection from predicting” their location. Since permanent checkpoints 

could not be built under these restrictions, and temporary ones had to be 

relocated at least once every 7 days, the checkpoints functioned as 

hybrids, or what we refer to as nonpermanent checkpoints that had 

neither the advantages of the physical infrastructure typical of permanent 

ones nor the flexibility of tactical checkpoints to respond to intelligence 

information.24 Such checkpoints do not have permanent infrastructure and 

hence lack the multiplicity of capabilities typically associated with 

permanent checkpoints in other sectors. At the same time, they also do 

not have tactical flexibility because they are generally kept at the same 

locations, which have been chosen by the Border Patrol in part for both 

safety and legal considerations. The checkpoint locations need to have 

adequate shoulder space on which to place the equipment needed to 

maintain the checkpoint, such as a small trailer, water tanks, portable 

lights and generators, as well as space to conduct secondary inspections of 

 23Omnibus Consolidated and Emergency Supplemental Appropriations Act, 1999, P.L. 105-

277 (1998); Consolidated Appropriations Act, 2000, P.L. 106-113 (1999); Appropriations for 

the District of Columbia, 2001, P.L. 106-553 (2000); Departments of Commerce, Justice, and 

State, the Judiciary, and Related Agencies Appropriations Act, 2002, P.L. 107-77 (2001); 

Consolidated Appropriations Resolution, 2003, P.L. 108-7 (2003); Department of Homeland 

Security Appropriations Act, 2004, P.L. 108-90 (2003); and Department of Homeland 

Security Appropriations Act, 2005, P.L. 108-334 (2004). 

24The rest of this report refers to these hybrid checkpoints in the Tucson sector as 

nonpermanent checkpoints. 

Legislative Restrictions on 

the Tucson Sector 
Page 25 GAO-05-435 Border Patrol 

vehicles ordered to pull over. The locations also need to have sufficient 

space to place signs in advance of the checkpoint to notify vehicles of the 

checkpoint’s location (to comply with legal decisions) and cannot be 

placed after or around sharp curves that might force vehicles to come to a 

sudden stop upon notice of the checkpoint. In addition, the checkpoint 

locations are chosen by the Border Patrol to maximize the likelihood that 

illegal entrants would have to transit through them in order to move 

northward. Depending on the criticality of their original location in terms 

of road networks and smuggling routes, relocating these checkpoints can 

reduce their effectiveness in monitoring vehicular traffic. (See app. III, fig. 

14, for a map of the sector and its checkpoints.) To support these 

nonpermanent checkpoints, the Tucson sector operates tactical 

checkpoints periodically, as occurs in other sectors with permanent 

checkpoints. 

The fiscal year 2005 Appropriations Act limited the funding prohibition to 

only construction, thus allowing the use of funds for site acquisition and 

design. Further, this act directed CBP to conduct a study of locations for 

proposed permanent checkpoints within the Tucson sector.25 In addition, 

the 2005 Act changed the requirement to relocate checkpoints to “at least 

an average of once every 14 days.” According to the Border Patrol, the 

phrase “an average” gave it more flexibility in determining checkpoint 

operating schedules than the previous years’ requirement of “at least once 

every 7 days.” As a result, in fiscal year 2005, the Patrol operates the 

checkpoint on I-19 for 14 days, closes it for 8 hours, and then reopens it for 

14 days. In addition, the Patrol has kept the checkpoint at the more 

northern kilometer post (KP) 42 location, because, it stated, moving it 

south to the KP 25 location every 7 days had permitted illegal immigrants 

to wait until KP 42 closed, and to then move north. At other checkpoints 

in the Tucson sector, the Patrol has maintained varying opening and 

closing schedules, which it stated were in conformity, in its view, with the 

“average of once every 14 days” language.26

 25Department of Homeland Security Appropriations Act, 2005, P.L. 108-334 (2004). The act 

calls for a plan for expenditure that includes location, design, costs, and benefits of each 

proposed permanent checkpoint. This study was submitted by CBP to the committee in 

April 2005. 

26We did not verify whether these schedules are carried out as stated. However, we did 

obtain copies of the records maintained by the Tucson sector that record the times that the 

I-19 and other Tucson checkpoints have been opened and closed. 
Page 26 GAO-05-435 Border Patrol 

However, as reported by the House Appropriations Committee, the fiscal 

year 2006 appropriations bill would restore the 7-day relocation 

requirement. Also, it provides that no funds may be used for site 

acquisition, design, or construction of permanent checkpoints in this 

sector.27

Prior to the implementation of INS’s southwest border strategy in 1993, the 

Tucson sector had a smaller volume of illegal alien traffic relative to the 

San Diego and El Paso sectors, as indirectly measured by apprehensions. 

In fiscal year 1993, the Tucson sector had less than one-fifth as many 

apprehensions as the San Diego sector, and less than one-third those in the 

El Paso sector. As the strategy unfolded, the San Diego and El Paso 

sectors became more difficult for illegal aliens to cross, while the volume 

of illegal traffic in the Tucson sector increased nearly sevenfold over the 

period of fiscal years 1993-2000, as measured indirectly by sectorwide 

apprehensions. This increase in illegal activity, as well as a general 

increase in legitimate vehicular traffic, led the Border Patrol to consider a 

more permanent presence for checkpoints in the Tucson sector, where it 

had previously operated only tactical checkpoints, to provide the range of 

facilities offered by permanent checkpoints. 

The Border Patrol started implementing the 7-day relocation requirement 

in June 2002, as noted above. Patrol officials told us that where feasible, 

taking safety and operational strategy into account, they alternated the 

sites of nonpermanent checkpoints along the same route in the Tucson 

sector. The Border Patrol was able to establish nonpermanent 

checkpoints among alternate sites on two such routes. However, for 3 of 

the 6 checkpoints in the sector, safety factors precluded use of other 

locations on the same route, and the Border Patrol closed the checkpoints 

for 7 days. (One checkpoint of the 6 closes each night and is replaced with 

roving vehicle patrols, because of the very sparse population of the region 

in which it is located.)28 The 7-day relocation rule was changed to “at least 

 27Department of Homeland Security Appropriations Act, 2006, H.R. 2360, 109th Cong. 

(Reported out of the House Appropriations Committee May 13, 2005.) 

28Because we made site visits to checkpoints only at specific times during one trip to this 

sector, and did not remain at these locations for days or longer, we did not verify whether 

the Border Patrol did, in fact, relocate or close its checkpoints on the schedule described to 

us. 

The Tucson Sector’s 

Nonpermanent 

Checkpoints Have 

Additional Limitations 
Page 27 GAO-05-435 Border Patrol 

an average of once every 14 days” in fiscal year 2005 appropriations 

legislation.29

The Border Patrol told us that it did not seek to evade compliance with the 

intent of the relocation rule by opening an alternative checkpoint just a 

short distance from the first one, or by closing for just a few hours. It did 

attempt to close and open for a few days at a time, they said, to try to 

confuse illegal aliens and contraband smugglers. However, officials stated 

that this was not productive, as the smugglers monitored the checkpoint 

activities so closely. According to Border Patrol officials, the funding 

prohibition on constructing checkpoints in the Tucson sector, in 

combination with the mandated relocation on a regular basis, allows 

smugglers and illegal aliens to further their entry into the United States 

with reduced interdiction risk. Table 1 shows the variations followed by 

the Border Patrol in operating the nonpermanent checkpoints in the 

Tucson sector. 

Table 1: Tucson Sector Nonpermanent Checkpoints Schedule to Conform to Legislative Language 

Checkpoint Open, Closure, and Relocation Schedule to Conform to Legislative Language 

A Opens when port of entry south of location is open and closes every night 

B Opens and closes for periods of time to comply with legislative language 

Does not relocate because there is no safe alternate location 

C Opens and closes for periods of time to comply with legislative language 

Does not relocate because there is no safe alternate location 

D Checkpoint alternates between KP 42 and KP 25 

E Checkpoint alternates among 3 identified locations along state route (SR) 82 or SR 83 

F Opens and closes for periods of time to comply with legislative language 

Does not relocate because there is no safe alternate location 

Source: Border Patrol. 

According to Border Patrol officials, contraband smugglers and illegal 

aliens typically wait until they learn from confederates that a checkpoint is 

in the process of being relocated or has been closed, and then use this 

downtime to further their illegal entry. Border Patrol officials told us that 

in today’s environment, they are up against increasingly sophisticated 

smugglers who use radios, cell phones, global positioning systems, and 

 29Department of Homeland Security Appropriations Act, 2005, P.L. 108-334 (2004). 
Page 28 GAO-05-435 Border Patrol 

other high-technology equipment to watch agents’ movements and alert 

each other when checkpoints are moved or closed. 

On highway I-19, the interstate highway that runs from Nogales, Arizona, 

on the border, directly north to Tucson, the Border Patrol alternated 

between two locations for nonpermanent checkpoints, at KP 42 and at KP 

25, at congressional staff instruction (for the last quarter of fiscal year 

2002), and then in conformity with the legislative restrictions for fiscal 

years 2003 and 2004. When the northern one (KP 42) was open, however, 

the Border Patrol told us that illegal aliens and smugglers who had made it 

over the border then waited in communities south of it, but north of KP 25. 

(See app. III, fig. 14 for a sector map that shows these locations.) When 

the checkpoint at KP 42 closed and moved down to KP 25, the illegal 

entrants who waited north of KP 25 (but south of KP 42 while open) were 

able to move with reduced interdiction risk, because there was no longer a 

checkpoint north of them. In fiscal year 2005, as noted above, the Border 

Patrol has maintained the checkpoint at the more northern KP 42 location, 

to reduce the potential for illegal entrants taking advantage of the 

relocation that occurred in previous years. In addition, the checkpoint is 

kept open for 14 days, then closed for 8 hours, and then reopened for 14 

days. The Border Patrol stated that it believes that this schedule conforms 

to the fiscal year legislative language that requires that Tucson sector 

checkpoints be relocated an average of at least once every 14 days. 

Border Patrol officials told us that without the infrastructure typical of the 

Patrol’s permanent checkpoints in others sectors, the Tucson sector 

cannot perform the full range of enforcement functions. For example, 

without access to national databases, suspects detained at the sector’s 

nonpermanent checkpoints cannot be readily identified and must be 

transported by an agent or agents to a Border Patrol station with database 

access, in order to determine if the persons should be detained. Further, 

the nonpermanent Tucson checkpoints lack paved, adequately large, level, 

off-road shoulder areas to deploy vehicle lifts or VACIS trucks required to 

examine underneath and inside vehicles. According to the Border Patrol, 

because detention facilities at these checkpoints are small rooms in 

mobile trailers, with weak internal doors and locks, they can be 

insufficient in size and security. (See photo in fig. 8.) Upon apprehension 

of a suspect or suspects, Border Patrol agents from the checkpoint must 

transport them to a station with adequate facilities for detention and 

processing, as would be found at typical permanent checkpoints 

elsewhere. The Border Patrol stated that sending an agent or agents to a 

station with suspects is an inefficient use of personnel and can cause the 

nonpermanent checkpoint to close because of personnel shortages. 
Page 29 GAO-05-435 Border Patrol 

Figure 8 shows photographs of the nonpermanent checkpoint operated on 

I-19 in the Tucson sector at KP 42, with limited facilities, located under an 

overpass to provide shelter from sun and weather, and lacking a paved 

shoulder for vehicles pulled over for further inspection. 

Figure 8: Tucson Sector Nonpermanent Checkpoint at KP 42 on I-19, Near Tubac, Arizona 

Although total apprehensions and contraband seizure data are available 

for interior checkpoints, some of the benefits—such as deterrence of 

potential contraband smugglers or of persons contemplating illegal entry 

into the United States—and costs of traffic checkpoints are difficult to 

quantify because deterrence is difficult to measure and cost data are not 

maintained separately by the Border Patrol for permanent or tactical 

checkpoints. Studies or reports on checkpoint benefits and costs have 

also not been performed by the Border Patrol. Of the less quantifiable 

benefits that can be described, we were told that intelligence debriefings 

of apprehended aliens and smugglers testify to the deterrent effects of 

interior checkpoints. In addition, local citizens and community groups 

with whom we met who live near or in the vicinity of interior checkpoints 

are generally supportive. However, this support is not universal. 

The most readily available data on the benefits of interior checkpoints are 

the drug seizure and apprehension data recorded by the Border Patrol on a 

daily basis at its checkpoints and stations. In fiscal year 2004, for example, 

the Border Patrol reported that the southwest interior checkpoints, which 

were staffed by about 10 percent of Border Patrol agents in those sectors, 

were responsible for 96,000 illegal alien apprehensions, or 8 percent of all 

Border Patrol apprehensions, and for seizure of 418,102 pounds of 

Benefits and Costs of 

Traffic Checkpoints 

Are Difficult to 

Quantify, but Some 

Examples Are 

Available 

Apprehensions and Drug 

Seizure Benefits 

Source: GAO.
Page 30 GAO-05-435 Border Patrol 

marijuana and 10,853 pounds of cocaine in fiscal year 2004, or about 31 

percent of the marijuana and about 74 percent of the cocaine seized 

nationally by the Border Patrol. 

In addition to the benefits of seizing contraband, and mitigating the 

smuggling of humans, there were at least six incidents reported to us 

where individuals with suspected ties to terrorism were identified when 

transiting a Border Patrol interior checkpoint and appropriate actions 

were coordinated with the FBI.30

Intelligence debriefings of smugglers and illegal aliens and reports of 

increased smuggling costs provide some evidence of checkpoints’ 

deterrent effect. Information from debriefings suggests that interior 

checkpoints deter some persons from attempting to go through them, and 

also push them into rural areas that are more difficult to transit and where 

they are more easily identifiable among a lower volume of traffic. In 

addition, the presence of effective checkpoints can contribute to increased 

smuggling costs, also possibly serving as a deterrent, according to the 

Border Patrol. In the San Diego sector, for example, we were told by the 

Border Patrol that smuggling fees charged to Mexicans and others had 

increased fivefold in recent years (to about $1,500 per person), because of 

the perceived difficulty of breaching border defenses and of transiting 

through interior checkpoints undetected. It is difficult, however, to 

separate out the contribution to deterring potential illegal entrants from 

entering the United States of increases in smuggling fees that are due to 

better line watch and line patrol border operations versus those cost 

increases that could be attributed to vigilance at interior checkpoints. (We 

did not validate the Border Patrol’s statements with regard to increased 

smuggling fees.) 

Evidence for the deterrent effects of checkpoints was reported in a 1995 

INS study which found that that smugglers and illegal aliens adjust their 

transit routes because they are well aware when checkpoints are open and 

closed.31 The 1995 study reported on a test of interior checkpoint 

operations in which the permanent checkpoint on I-5, near San Clemente, 

 30Border Patrol personnel informed us that the term “appropriate actions” is intentionally 

vague because of the sensitive nature of this information. 

31Office of Policy and Planning, Immigration and Naturalization Service, U.S. Department of 

Justice, Evaluation of Traffic Checkpoints at San Clemente and Temecula, June 1995. 

Deterrence and Some 

Other Potential Benefits of 

Traffic Checkpoints are 

Difficult to Quantify 
Page 31 GAO-05-435 Border Patrol 

California, was closed several times, in order to determine the impact of 

the checkpoint on I-15, near Temecula, California. The latter is located 

inland on a parallel major north-south highway, and about as far north of 

the border as the checkpoint on I-5. (See app. II, fig. 10, for a map of this 

sector that shows the location of these checkpoints.) The study reported 

that when the I-5, San Clemente checkpoint was closed, apprehensions at 

the I-15 Temecula checkpoint fell sharply—there was a 50 percent decline 

in 1 month. According to the study, this demonstrated that illegal entrants 

became aware of the closure and therefore chose the I-5 San Clemente 

route with no checkpoint, while avoiding the I-15 Temecula route with an 

operating checkpoint. The Border Patrol told us that this demonstrated 

the interdependence of various checkpoints operations and that illegal 

entrants were, in fact, deterred from transiting routes with checkpoints 

when unmonitored alternatives are available. This study, however, did not 

address whether the checkpoints completely deter any aliens from 

entering the country. 

As additional illustrations of the potential effects of interior checkpoints, 

Temecula station officials described the following operations that in their 

view appeared to confirm that illegal aliens had changed their intended 

routes in order to avoid the checkpoints at Temecula and San Clemente:32

• San Diego sector intelligence analysts determined that illegal alien 

smugglers were avoiding the permanent Border Patrol interior 

checkpoints on the highways at San Clemente (I-5) and Temecula (I15). Instead, they were taking a circuitous route from the San Diego 

area to eastern California and western Arizona, and then turning north 

on secondary highways without checkpoints to make their way to Los 

Angeles. In response to this intelligence, the Temecula station set up 

an August 2004 3-day traffic observation operation along I-10 between 

Los Angeles and Arizona. During the operation, Border Patrol agents 

stopped 30 suspect vehicles, and apprehended 134 illegal aliens. 

Border Patrol officials confirmed the earlier intelligence that illegal 

aliens were utilizing the I-10 route, without checkpoints, to avoid 

checkpoints on I-5 and I-15. The officials believe that this 

demonstrated the effectiveness of the permanent I-5 and I-15 interior 

checkpoints as deterrents that cause illegal entrants to seek out less 

traveled, unmonitored alternative routes, even if longer in distance and 

time required to reach major U.S. cities. 

 32We did not confirm these operational results or the benefits claimed by officials. 
Page 32 GAO-05-435 Border Patrol 

• On May 3, 2004, three vans ran (transited without stopping despite 

orders to do so) the Otay Mesa port of entry near San Diego, and two 

vans proceeded north on I-15 (one was stopped near the port of entry). 

Temecula station officials were alerted to the fleeing vans and were 

notified that to avoid the checkpoint on I-15, the vans had turned onto a 

secondary road that roughly paralleled the interstate. Four tactical 

checkpoints were operating in the area, and the vans were stopped by 

agents at two of these checkpoints. A total of 48 illegal aliens were 

arrested. According to Temecula station officials, this incident showed 

that (1) illegal alien smugglers know that the permanent checkpoints 

such as the one on I-15 are to be avoided if possible, and (2) tactical 

checkpoints on secondary roads are valuable and effective for 

apprehending aliens attempting to circumvent checkpoints on major 

highways. 

• Temecula station officials described another operation as an example 

of checkpoint deterrence effectiveness. On the basis of intelligence, 

Temecula station intelligence analysts concluded that smugglers of 

illegal aliens had altered their entry routes to avoid the significant 

Border Patrol presence in the San Diego sector. These altered entry 

routes included the use of I-40 westbound to enter the greater Los 

Angeles area; the Border Patrol did not have checkpoints or a constant 

presence on westbound I-40. In response to this intelligence, the 

Temecula station conducted a traffic observation operation with 

multiple marked patrol vehicles on I-40 over a period of 3 days in 

November 2004, to interdict alien smugglers using the westbound I-40 

corridor to circumvent the permanent checkpoints on I-5 and I-15. The 

I-40 operation was conducted shortly after a Border Patrol I-10 

operation with the expectation that smugglers would use I-40 to avoid 

I-10. The Border Patrol operation found 7 vehicles with 77 illegal 

aliens. Of these, 60 had entered the country east of the San Diego 

sector, circumventing the I-5 and I-15 checkpoints. According to 

Temecula station officials, this confirmed that I-40 is a major smuggling 

route and that the permanent checkpoints on I-5 and on I-15 serve as 

deterrents to at least some illegal traffic, as intended. 
Page 33 GAO-05-435 Border Patrol 

Local law enforcement, business, and community leaders near interior 

traffic checkpoints in Temecula, California, in the San Diego sector, and 

Nogales, Arizona, in the Tucson sector, that we interviewed told us that in 

their view, the checkpoints and the presence of Border Patrol agents were 

of considerable benefit to their communities. However, in the small 

community of Tubac, Arizona, we found local criticism of interior traffic 

checkpoints.33 Since we did not conduct a comprehensive survey of all 

communities in the vicinity of all 33 permanent checkpoints in the 

southwest border states, our findings are limited to the views of the local 

citizens and law enforcement officials with whom we met in the 

communities we visited, as well as statements by the Border Patrol with 

regard to their relationships with local communities near checkpoints. We 

did not confirm the views expressed by these citizens and officials, as little 

data were available relating directly to their statements. 

Officials representing the city of Temecula, California, the Temecula 

Police Department, and the Chamber of Commerce, for example, all said 

that the nearby I-15 traffic checkpoint and Border Patrol presence benefit 

their community.34 The checkpoint has the second greatest average daily 

volume of vehicular traffic among the Border Patrol’s checkpoints, with 

about 122,000 vehicles passing through the checkpoint location daily. City 

and police officials said that having the checkpoint in operation means 

that illegal aliens and drug smugglers are intercepted and taken off the 

streets, reducing crime and vandalism. One city official also said that 

traffic problems with the checkpoint have been minimal, and that the city 

has received very few calls complaining about the checkpoint and what 

amount to minimal delays when the checkpoint is operating and checking 

traffic. The official said that the majority of the calls that the city received 

were before September 11, 2001, and very few calls had been received 

since then. The President of the Temecula Chamber of Commerce 

conducted an informal survey of member businesses, and only one 

business mentioned that some employees said that the checkpoint 

 33The interior checkpoint near Temecula is the one on I-15. The interior checkpoint near 

Tubac and Nogales, Arizona, is the one that alternated between a road location designated 

as KP 25 and KP 42 on I-19. Tubac is located just off I-19, near KP 42. According to the 

Border Patrol, the KP designations stem from a time when the metric system was being 

proposed as an alternative to the English system of measurement. 

34Temecula, California had an estimated 2004 population of about 82,000. It is in Riverside 

county, the fifth most populous in California, with 1.87 million persons in 2004. These and 

other population data were obtained from the U.S. Census, 2000, or later updates on the 

U.S. Census Web site, if available. 

Most Local Community 

Leaders We Contacted See 

Traffic Checkpoints as 

Benefiting their 

Communities 
Page 34 GAO-05-435 Border Patrol 

operations occasionally delayed their commute to or from work. Overall, 

the Chamber President concluded that the checkpoint is not a concern to 

the community. 

The Santa Cruz County Attorney from Nogales, Arizona, told us that the 

Border Patrol and its checkpoints were among the best protections for 

fighting illegal alien traffic and local crime, with a side benefit of detecting 

drunk drivers on their way back from Mexico. According to this official, 

the I-19 checkpoint between Nogales and Tucson was a major benefit to 

the community because it was saving lives, apprehending illegal aliens, 

and arresting drug smugglers. The official also stated that, in her opinion, 

the checkpoints are effective in apprehending drug violators out of 

proportion to the resources deployed at the checkpoints and voiced the 

view that permanent checkpoints were better than tactical ones. 

In contrast to the generally positive view of the benefits resulting from the 

Border Patrol checkpoints from others that we interviewed, the president 

of a local civic association from Tubac, Arizona (population 949), located 

between Nogales and Tucson near the I-19 nonpermanent Tucson sector 

checkpoint at KP 42, told us that he believed the checkpoint was 

disruptive to the community and was not effective because illegal aliens 

were circumventing the checkpoint and passing through the community. 

He said that the checkpoint had affected home sales and housing values, 

and that most local residents were strongly opposed to having a 

permanent checkpoint built near them on I-19, because of fears about the 

impact on traffic congestion and overall quality of life. We were also told 

by congressional staff that the overwhelming majority present at April and 

July 2005 community meetings in Tubac had voiced opposition to the 

possibility of a permanent checkpoint on I-19 near Tubac. 

The Border Patrol Handbook states that checkpoint operations should be 

suspended if there is “too much traffic congestion” and does not further 

define this. However, some sector checkpoints have more precise 

guidance pertaining to a specific distance or length of time traffic will be 

permitted to back up. Agents said they know from experience the amount 

of wait time that is created by how far back from the checkpoint the lines 

of vehicles extend. The maximum delays that we observed appeared not 

to exceed the restrictions defined by the checkpoint guidance prepared by 

Traffic Congestion at 

Checkpoints Does Not 

Appear to Be a Large 

Problem but May Involve 

Some Costs 
Page 35 GAO-05-435 Border Patrol 

certain sectors.35 This was the case, for example, at I-5 near San Clemente, 

which has the single greatest daily volume of traffic in the country (about 

144,000 vehicles per day) among interior Border Patrol checkpoints, and at 

I-15 near Temecula, the next highest, with about 122,000 vehicles daily. At 

the times we visited, at both locations, we observed that the agents 

temporarily stopped checkpoint inspections when estimated delays 

exceeded guidelines. Traffic was then “flushed” and permitted to flow 

through until there was no line of waiting vehicles. Screening operations 

were then resumed. We also observed during our visit to the San 

Clemente checkpoint, traffic flow in the opposite southerly direction, 

where there is no checkpoint, sometimes was heavier and slower than on 

the side with the ongoing checkpoint operation. 

Moreover, of the more than 400 statewide cameras maintained by the 

California Department of Transportation to monitor traffic, none are at 

either the Temecula or San Clemente checkpoints, according to the 

department. In response to our questions, the department stated that it 

had not received reports in recent years on congestion or related problems 

at either the I-5 or I-15 checkpoints, and it had not conducted studies of 

the checkpoints. 

We contacted several other organizations that monitor traffic congestion 

as part of their work, such as the Automobile Club of Southern California, 

and the California Highway Patrol, to ask if they had received complaints 

about the San Clemente or Temecula checkpoints in California, or had 

observed actual traffic backups at these checkpoints. We also asked the 

American Trucking Associations if it had received complaints from 

commercial shippers about checkpoints in the southwestern states. None 

of these organizations cited complaints in recent years about these 

checkpoints. 

In addition, an official of an organization that promotes economic 

development in Laredo, Texas, and who is active in monitoring the impact 

on traffic of the checkpoint on I-35 north of Laredo, stated that traffic 

delays were minimal even at the I-35 checkpoint, and that anyone living on 

 35According to the Border Patrol, sectors do not issue or direct specific traffic control 

policy for individual checkpoints other than the national “general” policy. Most sectors 

have required stations to develop specific traffic control guidelines for each checkpoint. 

These guidelines are often in the traffic control plan of the checkpoint permit or memo 

form. The rationale, according to the Border Patrol, is that every checkpoint is different 

and requires different guidelines. 
Page 36 GAO-05-435 Border Patrol 

or near the border is familiar with the checkpoints as a fact of life. He 

believed that commercial truckers build in potential travel delays, which 

are longer for commercial vehicles than for cars, into their cost of doing 

business and transit times. He noted that even during rush hours, he 

believed that trucks did not wait more than an average of about 20 minutes 

maximum, based on what he had observed in recent years. Cars are 

delayed considerably less, averaging perhaps a 5-minute delay in rush 

hour, he stated. We observed this checkpoint, and delays appeared not to 

exceed 5 minutes at the time we visited, based on the time that it took for 

cars at the back of the line to transit through the checkpoint. 

At the tactical checkpoint on I-19 between Nogales and Tucson, Arizona, 

we saw minor traffic backups of not more than about a half dozen vehicles 

at any time over the course of about 1 hour. We were told that this was 

typical for this time of year; delays did not last more than 2 or 3 minutes 

for vehicles transiting the checkpoint during our site visit. However, the 

Border Patrol also told us that when truck traffic is particularly heavy 

during the spring harvest season, pulling trucks over to the side of the 

road to inspect them can create backups that cause safety problems and 

delays for the truck drivers. 

We also observed traffic patterns at permanent checkpoints on I-35 north 

of Laredo and on U.S. highway 281 at Falfurrias, Texas, both major 

highways, and at a permanent checkpoint at Hebbronville, Texas, on a 

secondary road between Falfurrias and Laredo. Although traffic backups 

occurred on occasion at these locations, we were told that they generally 

did not last more than a few minutes, as additional agents or lanes are 

added to reduce delays. During our visit, Border Patrol agents appeared to 

be monitoring the amount of traffic waiting in line, which caused less than 

about 5 minutes’ wait time, and usually less. Agents told us that if traffic 

backs up, they add extra agents to the inspection lanes, and may open 

additional lanes as well.36 At some holiday periods, however, we were told 

delays can reach 20 to 30 minutes. The volume of traffic at the Texas 

checkpoints we observed was much lower than that on I-5 and I-15 in 

California, permitting what amounts to a near 100 percent check of 

transiting vehicles, according to the Border Patrol. This is feasible when 

 36At all three of these permanent checkpoints in Texas, there are paved shoulder areas with 

multiple lanes to funnel traffic away from the actual highways. This not only permits 

separating the commercial trucks from passenger vehicles, but also makes the entire 

inspection process safer for everyone, as there are fewer backups onto the highways, 

according to Border Patrol officials. 
Page 37 GAO-05-435 Border Patrol 

average daily traffic volume is about 13,700 vehicles, as is the case at the 

Laredo, Texas, checkpoint, compared with more than 120,000 at I-15, near 

Temecula, California, or over 140,000 at I-5, near San Clemente, California. 

Border Patrol officials told us that costs of operating the permanent and 

tactical checkpoints are not routinely or systematically maintained or 

reported because checkpoints are integral and interdependent parts of the 

multilayered enforcement strategy. As such, permanent and tactical 

checkpoints are supported with facilities, personnel, equipment, and 

canines, for example, and by their associated stations, which in turn are 

supported by the sector as a whole. Tactical checkpoints in particular are 

often set up specifically to support the permanent ones, often on a 

changing daily basis. Agent manpower levels may also vary at both the 

permanent and the tactical checkpoints, depending on how the Border 

Patrol decides on a given day to best allocate personnel resources, in 

response to traffic volume, intelligence on illegal entrant routes, and other 

factors, such as weather. For example, the permanent checkpoint at I-15 

Temecula is supported by up to eight tactical checkpoints that are set up 

as needed, based on intelligence data on illegal alien traffic on the sector’s 

secondary roads. 

The costs of one tactical checkpoint versus another are not readily 

separable, except perhaps the personnel costs, and even then, those could 

vary over a period of hours, according to Border Patrol officials. A 

question that the Border Patrol officials asked and which has no easy or 

standard answer was “If an agent must transport arrested aliens or 

smugglers to a station headquarters, should his/her salary be counted as 

part of the roadside checkpoint, or the station headquarters support?” 

Even considering these obstacles to checkpoint cost comparisons, we 

asked Border Patrol officials whether they could supply us with individual 

checkpoint operating costs to include facilities, equipment, personnel, and 

any other costs. Border Patrol officials queried the sectors and stations at 

the locations we visited and asked whether cost data could be assembled. 

The sectors and stations responded with what cost data they could locate, 

but it was not possible to obtain similar data from each location, and the 

data provided would not be reliable enough to present any meaningful 

statistics concerning costs of operating interior traffic checkpoints. 

Costs of Operating 

Checkpoints are Not 

Routinely Maintained 
Page 38 GAO-05-435 Border Patrol 

In reviewing Border Patrol reports, and in discussions with Border Patrol 

officials, we found that the Border Patrol has not systematically evaluated 

the effectiveness of interior checkpoint operations. The Border Patrol 

does gather and report traditional law enforcement data, including the 

number of apprehensions, historical apprehension trends, and weight and 

type of contraband seized, but could not provide us with reports or 

analyses that assessed the performance of one sector compared to 

another, or of interior checkpoints compared with line operations. Thus, 

the Border Patrol does not have analyses based on inputs (costs), such as 

agent work years, divided into outputs, such as apprehensions or 

contraband seized, that could help measure effectiveness or productivity 

and that could therefore also be used in making decisions about how best 

to allocate resources. The Border Patrol stated that it has not evaluated 

the effectiveness of its interior checkpoints largely because checkpoints 

are part of a multilayered enforcement strategy and cannot be easily 

separated for evaluation purposes. Furthermore, officials stated that 

because such outcomes as deterrence are difficult to measure (i.e., 

estimating how many crimes or illegal entries were deterred before they 

happened), the Border Patrol has chosen to rely on the types of data cited 

above to gauge effectiveness. 

A key component to assessing unit operations is the development of 

performance measures. We have previously reported on the need for 

federal agencies to develop performance measures of their programs and 

to use such measures to improve their performance, as well as to be in 

compliance with the Government Performance and Results Act of 1993 

(GPRA).37 As we noted, under the act, “every major federal agency must 

now ask itself some basic questions: What is our mission? What are our 

goals and how will we achieve them? How can we measure our 

performance? How will we use that information to make improvements? 

GPRA forces a shift in the focus of federal agencies—away from such 

traditional concerns as staffing and activity levels and toward a single 

overriding issue: results. GPRA requires agencies to set goals, measure 

performance, and report on their accomplishments.”38

 37P.L. 103-62. 

38GAO, Executive Guide: Effectively Implementing the Government Performance and 

Results Act, GAO/GGD-96-118 (Washington, D.C.: June 1996), p. 1. See also, Program 

Evaluation: Studies Helped Agencies Measure or Explain Program Performance

GAO/GGD-00-204 (Washington, D.C.: September 2000). 

The Lack of 

Systematic Evaluation 

Limits the Border 

Patrol’s Ability to 

Allocate Resources 

Based on Need 
Page 39 GAO-05-435 Border Patrol 

Organizations use performance measures to help demonstrate the level of 

progress in achieving results, to inform decision makers, and to hold 

managers accountable. To better articulate a results orientation, 

organizations create a set of performance goals and measures that address 

important dimensions of program performance. Establishing and using 

performance measures for checkpoint operations and other strategy 

components would allow the Border Patrol to help assess the comparative 

success of each checkpoint in addressing program goals as well as 

checkpoints generally in comparison with line and patrol operations. A 

comparison of the effectiveness of each sector, using performance 

measures, would permit the Border Patrol to more meaningfully assess the 

success of its overall strategy than does a count of total apprehensions or 

contraband seizures. Without knowing how much effort produced an 

outcome—in this case, apprehensions or contraband seizures—it is 

difficult to know if one sector or region is performing better than another 

(on a per input basis). With such knowledge, more effective management 

strategies can be devised, if needed, to better allocate agency resources, in 

conjunction with other data and information. 

We acknowledge that developing performance measures applied to all 

checkpoints can be challenging for the reasons stated by Border Patrol 

officials. Nevertheless, it is important that the Border Patrol develop 

performance measures to gauge success in meeting strategic goals and 

that these measures go beyond the traditional output data it currently uses 

to indicate the effectiveness of law enforcement efforts. 

Although the Border Patrol told us that the legislative restrictions on 

funding for construction of checkpoints in the Tucson sector, combined 

with the requirement to relocate checkpoints on a 7- or 14-day schedule, 

had reduced their effectiveness, it did not have a data-based analysis to 

support these statements. It did have data, by sector, on apprehensions of 

illegal entrants at interior checkpoints and for line watch/line patrol, as 

well as for work hours charged at interior checkpoints and line watch/line 

patrol. (Agent work hour data have not been maintained by the Border 

Patrol for tactical checkpoints versus permanent ones and were therefore 

not available.) To test the feasibility of developing additional measures of 

performance that would address these concerns, we used Border Patrol 

data to measure apprehensions per agent work year and cost of 

apprehensions per agent work year. Such measures might help to 

determine if the available data support the Border Patrol’s statements on 

the impact of the legislative restrictions on the Tucson sector’s interior 

checkpoints effectiveness. 

Available Data Suggest 

That Legislative 

Restrictions on the Tucson 

Sector Reduced the 

Performance of Its Interior 

Checkpoints 
Page 40 GAO-05-435 Border Patrol 

In applying the apprehension per agent work year measure,39 we compared 

the performance of the Tucson sector interior checkpoints over the period 

of fiscal years 2001-2004 with those of the interior checkpoints in the three 

other sectors we visited. We limited the comparison to these four sectors 

because a considerable amount of the work hour data had to be collected 

by the Border Patrol through data calls, which placed a time burden on 

those collecting the data for us. We examined the data starting with fiscal 

year 2001, the last year for which the impact of the terror attacks of 

September 11 were largely not felt on illegal immigration,40 through fiscal 

year 2004, the last year for which data were available at the time of this 

report. Throughout this period as well, no funding had been permitted for 

construction of checkpoints in the Tucson sector. 

Our analysis of Border Patrol data suggest that, as measured in 

apprehensions per agent work year, the restrictions in the Tucson sector 

may have had a negative impact on the performance of its interior 

checkpoints, starting at about the time the sector implemented direction 

from congressional staff to relocate checkpoints every 7 days, in 

comparison with the three other sectors we visited, where no comparable 

decline in effectiveness occurred during the same time period. 41 

According to the Border Patrol, its records show that it began relocating 

the Tucson sector’s checkpoints every 7 days in June 2002, which meant 

closing some of them, as explained previously. 

Figure 9 shows the apprehensions per agent work year at interior 

checkpoints for each of the four sectors we visited, for fiscal years 2001-

2004, and the apprehensions per agent work year for line patrol/line watch 

along the border. 

 39As noted above, work years are total hours divided by 2,080 (a 40-hour week times 52 

weeks). Apprehensions per work year were calculated by dividing the number of agent 

hours at interior checkpoints and at line watch/line patrol work by 2,080. The resulting 

calculation of work years was then divided by the number of apprehensions attributed to 

line watch/line patrol and interior checkpoints, to calculate apprehensions per work year. 

40According to the Border Patrol, all southwest sectors experienced varying declines in 

illegal entries after the attacks of September 11 as a result of fears about enhanced U.S. 

security. However, since less than 3 weeks remained in fiscal year 2001 after the attacks, 

most of the impact would appear in fiscal year 2002 data, which started October 1, 2001. 

41We used the measure of apprehensions per agent work year in order to control for the 

number of hours worked. This meant, for example, that if a sector had 100 agent work 

years charged in a given year and 100 apprehensions, that the level of productivity or cost 

effectiveness was the same as in another sector with 10 agent work years charged, and 10 

apprehensions. 
Page 41 GAO-05-435 Border Patrol 

Figure 9: Apprehensions per Agent Work Year in the Tucson, San Diego, Laredo and McAllen Sectors, Fiscal Years 2001-2004 

Notes: Line/Patrol refers to line watch and line patrol Border Patrol operations, based on agent work 

hours charged by Border Patrol agents to those activities. Interior Checkpoint refers to work hours 

charged by agents for work at interior checkpoints—permanent and tactical in the San Diego, 

McAllen, and Laredo sectors; and nonpermanent in the Tucson, Arizona, sector. 

0

100

200

300

400

500

600

2001 2002 2003 2004

Apprehensions

Line/patrol

Interior checkpoint

Source: GAO analysis of Border Patrol data.

351

521

271 271

318

63

422

119

Fiscal year

0

100

200

300

400

500

600

2001 2002 2003 2004

Apprehensions

189

74

152

60

118

60

129

57

Fiscal year

Tuscon sector

Laredo sector

0

100

200

300

400

500

600

2001 2002 2003 2004

Apprehensions

115

51

116

50

134 119

138

191

Fiscal year

0

100

200

300

400

500

600

2001 2002 2003 2004

Apprehensions

105

242

91

214

71

260

87

272

Fiscal year

San Diego sector

McAllen sector
Page 42 GAO-05-435 Border Patrol 

Figure 9 shows that apprehensions per agent work year at the Tucson 

sector interior checkpoints fell 48 percent from fiscal year 2001 to fiscal 

year 2002, when the 7-day relocation procedures were put into effect, with 

about 4 months remaining in the fiscal year. This was followed by a 77 

percent decrease from fiscal year 2002 to fiscal year 2003, when the 7-day 

relocation requirement was in effect for the entire fiscal year. The overall 

decrease from fiscal year 2001 to fiscal year 2003 was about 88 percent, in 

the Tucson sector. Apprehensions per agent work year rose from fiscal 

year 2003 to fiscal year 2004, but the 2004 level was 77 percent below the 

fiscal year 2001 level. In contrast to these performance measures for the 

Tucson sector interior checkpoints, apprehensions per agent work year 

for same period at the interior checkpoints in the three other southwest 

sectors (San Diego, California; Laredo, Texas; and McAllen, Texas) we 

visited—that were not subject to the funding restrictions or the relocation 

requirements—either stayed at about the same level over this period or 

increased somewhat.42

During fiscal year 2001 to 2002, when Tucson apprehensions per agent 

work year fell 48 percent, apprehensions per agent work year fell less than 

2 percent in the San Diego sector, decreased about 19 percent in the 

Laredo sector, and decreased about 12 percent in the McAllen sector. The 

Border Patrol attributed the drop in apprehensions in these and other 

sectors in this period to a general decrease in illegal border crossings after 

September 11 but attributed the greater decline in the Tucson sector to 

relocating the Tucson checkpoints on a regular 7-day basis, starting in 

June 2002. Border Patrol officials told us that they were not aware of any 

other changes or factors that would have caused the reduction in Tucson 

compared with other sectors other than the combination of the funding 

restrictions and the 7-day relocation requirement. 

Moreover, apprehensions per agent work year at interior checkpoints in 

the Tucson sector fell by about 77 percent from fiscal year 2002 to fiscal 

year 2003, while they either remained about the same or increased (more 

than doubling in San Diego) in that period in the other three sectors. In 

the San Diego sector, interior checkpoint apprehensions per agent year 

increased about 60 percent from 2003 to 2004 and were almost four times 

the 2002 level (versus Tucson, where the 2004 level was 55 percent below 

 42GAO did not validate the data provided by the Border Patrol on apprehensions, drug 

seizures, or vehicle counts. However, we did determine that the Border Patrol utilizes 

processes and checks that provide reasonable assurance that the data recorded for 

apprehensions and drug seizures are accurate. 
Page 43 GAO-05-435 Border Patrol 

the 2002 level). In the McAllen and Laredo sectors, there was almost no 

difference in checkpoint apprehension rates between 2003 and 2004. The 

Border Patrol believes that the differences between the Tucson sector and 

others with regard to interior checkpoint performance are in large part the 

result of the requirement to relocate checkpoints every 7 days at that time. 

Border Patrol officials stated that the smugglers can easily determine 

when the tactical or nonpermanent checkpoints in any location must 

relocate or close and are therefore able to evade them by waiting until 

they move or close, and a potential vulnerability in border security has 

been created. 

It is important to note that we did not evaluate all the factors that might 

have contributed to the differing performance results between Tucson 

interior checkpoints and those in the other three sectors. There could 

have been other factors beyond the restrictions on construction of 

checkpoints and the requirement to relocate every 7 days that affected 

checkpoint performance, such as the unknown number of persons 

attempting entry into a sector, varying topographic conditions and road 

networks, and the fees charged by smugglers to smuggle illegal immigrants 

into the United States. Nevertheless, while there may have been other 

factors that affected the performance of interior checkpoints in the four 

sectors, the data in figure 9 should not be overlooked when considering 

the results or impacts of policy or management directives. 

In the second performance measure, we converted the apprehensions per 

agent work year into costs of apprehensions per work year, or cost per 

apprehension.43 We then compared interior checkpoints cost per 

apprehension (per work year) with costs per apprehension (per work 

year) for line watch and line patrol operations. We were unable to develop 

costs per apprehension at permanent versus tactical checkpoints because 

individual checkpoint cost data are not maintained by the Border Patrol. 

In addition, this measure is based on agent labor costs at interior 

checkpoints and line watch/line patrol and does not include overhead 

costs, such as those for equipment, training, buildings, canines, and so 

forth. Converting the fiscal year 2004 apprehension data into cost per 

apprehension (per work year), apprehensions in the San Diego sector at 

 43Costs of apprehensions per work year were calculated by dividing the average cost of an 

agent work year in fiscal year 2004, $53,000, by the number of apprehensions per work year 

reported for checkpoints, such as 191 apprehensions per work year in fiscal year 2004 at 

interior checkpoints in the San Diego sector. In this instance, $53,000 divided by 191 

produced a cost per apprehension per work year of $277. 
Page 44 GAO-05-435 Border Patrol 

the border (line watch/line patrol) cost $384 per apprehension, and about 

$277 per apprehension at the interior checkpoints (both permanent and 

tactical). In the Tucson sector, for the same fiscal year, border 

apprehensions cost $126 each per work year, and interior checkpoint 

apprehensions cost $445 each. 

These ranges of cost per apprehension (per work year) are not, however, 

necessarily reflective of agents at one checkpoint or in one sector working 

harder or more effectively than those in another sector and must be 

considered in the context of the Border Patrol’s integrated, multilayered 

strategy, which seeks to deter illegal entrants through the perceived risk of 

apprehension. Thus, a permanent checkpoint with a substantial 

infrastructure may have many agents, such as at I-5 near San Clemente 

(with about 100 agents assigned to the location) but may have 

comparatively few apprehensions—because it has successfully deterred 

potential illegal entrants. In Temecula, California, agents are required to 

monitor alternative routes through the hills around the I-15 permanent 

checkpoint. Again, many agents may be required, but few apprehensions 

may occur, if illegal entrants are deterred to alternative routes, such as the 

circuitous I-10 route previously described. In contrast, a sector with many 

illegal entrants, such as Tucson, may effect many apprehensions because 

of the volume of illegal entrants, seemingly showing border cost per 

apprehension to be much lower than in San Diego. Yet the reality is that 

the long-term legacy INS and now CBP strategy of closing off the easiest 

routes (in San Diego, El Paso, and McAllen), has led to the high volume in 

the Tucson sector. Therefore, cost per apprehension or any other single 

performance measure cannot be used without taking into account the 

overall strategy. 

While a performance measure such as cost per apprehension can provide 

some information on cost-effectiveness, several additional caveats exist. 

First, regarding the output measured in the denominator (i.e., the number 

of apprehensions per agent work year, such as 191 for San Diego in fiscal 

year 2004), some apprehensions may be considered more important to the 

agency than others. For instance, apprehending a drug smuggler or a 

terrorist might be considered more important than apprehending an illegal 

alien job seeker. Second, regarding the cost of inputs measured in the 

numerator (e.g., the $53,000 annual average agent nationwide salary), 

numerous cost measures can exist. The most easily applied is often the 

variable cost of labor that is used above and which may require estimation. 

Other input costs may exist but may be difficult to assign to a given 

apprehension, since not only are indirect overhead costs involved (e.g., 

training, equipment, infrastructure, canines), but also such costs as the 
Page 45 GAO-05-435 Border Patrol 

differing salaries of multiple agents, if more than one was involved in the 

apprehension; the time used up by each different agent; and the processing 

costs, which can vary by suspect, depending on whether the person is 

already in a national database or cannot be identified. 

The two performance measures we developed would not alone fully assess 

or explain relative success among sectors, and in developing performance 

measures for checkpoints, a number of factors would need to be 

considered. For example, in comparing the apprehensions per agent work 

year and cost per apprehension for the adjacent McAllen and Laredo 

sectors, considerable differences appear, with McAllen checkpoints 

apprehending far more illegal aliens per agent work year than Laredo. 

Converted into cost per apprehension, these data show that for fiscal year 

2004, in the Laredo sector, the cost per apprehension for line watch/line 

patrol was $411, while the cost per apprehension at checkpoints was $930 

each. For McAllen, the cost per apprehension at line/patrol was $609, 

while the cost at the checkpoints was $195 per apprehension. 

Taken alone, and without additional information about conditions in these 

sectors, these costs per apprehension are not necessarily a useful guide to 

management decisions about resource allocation. As Border Patrol 

officials told us, several factors are believed to contribute to the 

differences in apprehension patterns between McAllen and Laredo sectors. 

These include the topography, availability of egress routes, staff 

deployment, and varying expedited removal programs. Further, the 

McAllen sector includes two major Mexican cities adjacent to its border 

with a combined population of about 2 million people and an 

infrastructure that facilitates potential illegal entrants. These factors 

provide context to the analysis and underscore the importance of the 

Border Patrol developing a range of performance measures that can 

adequately account for differences among sectors and provide decision 

makers with reliable indicators of success. 

The usefulness of these measures notwithstanding, other performance 

measures and relevant factors would also be useful in assessing the 

effectiveness of checkpoints relative to other elements of the multilayered 

strategy. Some available information, beyond apprehensions and 

contraband seized, could help the Border Patrol make more informed 

decisions about where its operations are most effective and how best to 

allocate resources to make needed improvements. For example, the 

Border Patrol could consider the cost of smuggling charged to illegal 

immigrants as a measure of its overall effectiveness. Additionally, the 

Additional Performance 

Measures Could Help 

Guide Management 

Decision Making 
Page 46 GAO-05-435 Border Patrol 

Border Patrol could consider the number of apprehensions or contraband 

seizures per the number of vehicles sent to secondary inspection as a 

measure of effectiveness. There are likely other measures that could use 

existing or easily gathered data to help measure effectiveness across the 

range of Border Patrol line watch, line patrol, and interior traffic 

checkpoint activities. These kinds of performance measures can aid in 

making resource allocation decisions, provided again that such decisions 

are made with reasonable knowledge of other conditions present in a 

given sector or region. 

It is unlikely that either the first two lines of border defense, line watch 

and line patrol, or the interior traffic checkpoints, another layer of 

defense, will ever be 100 percent effective in catching all smugglers or 

aliens illegally entering the United States. This is the case given the 1,950 

mile southwest border, the number of personnel and the cost required to 

cover all of this area, the continuing sophistication of smugglers using 

modern technology to observe and evade the Border Patrol’s enforcement 

efforts, and the differences in wages, job opportunities, and perceived life 

opportunities between Mexico and the United States. However, the 

Border Patrol’s interior traffic checkpoints—both permanent and 

tactical—have distinct functions in its integrated, multilayered strategy 

intended to detect and deter potential terrorists, illegal immigration, and 

contraband smuggling into the United States. While the permanent 

checkpoints are the anchors of this part of the strategy, the tactical 

checkpoints reinforce the permanent ones at those locations where 

smugglers, illegal aliens, or terrorists can use secondary roads to avoid the 

permanent checkpoints, and when intelligence can help direct 

redeployment of tactical checkpoints to counter new infiltration routes. 

Working in tandem, the interior checkpoints combine the high-technology 

capabilities and detention, processing, and inspection facilities of the 

permanent checkpoints with the element of flexibility that tactical 

checkpoints can offer. 

Trying to measure the effectiveness of its border enforcement deterrence 

strategy has been a long-standing challenge for legacy INS and now CBP 

and the Border Patrol. As many illegal aliens and contraband smugglers 

continue to evade the border defenses, the need to measure effectiveness 

and allocate scarce resources grows in significance. In its Performance 

and Annual Report, CBP uses traditional law enforcement effectiveness 

measures, such as numbers of apprehensions and contraband seizures to 

describe the Border Patrol’s performance. While these measures serve as 

worthwhile indicators, the annual reports do not compare the 

Conclusions 
Page 47 GAO-05-435 Border Patrol 

effectiveness of line watch and line patrol with the effectiveness of interior 

traffic checkpoints. These traditional measures also do not delineate the 

performance of permanent, tactical, and nonpermanent checkpoints. In 

contrast, performance measures that take inputs and outputs into account, 

such as agent work years divided by apprehensions, provide a basis for 

helping make decisions about how best to allocate agency resources, in 

conjunction with other information and data. Such measures can also 

help identify trends that might otherwise not be apparent using traditional 

data, as shown by our analysis of the data on performance of the Tucson 

sector nonpermanent interior checkpoints compared with the 

performance of other sectors. Apprehension data alone would not have 

shown the trend of the decrease in apprehensions per agent work year 

that occurred at the Tucson sector checkpoints, starting at about the same 

time the 7-day relocation requirement went into effect, while no 

comparable decrease occurred in the three other sectors without the 

requirement. 

Moreover, apprehensions per agent work year, and the cost per 

apprehension, along with information on many other relevant factors, 

could provide useful trend information on the relative cost efficiency of 

these components of the multilayered enforcement strategy. Other 

measures of performance and effectiveness might also be developed using 

existing or easily gathered information to assess checkpoint operations 

and performance, as well as other border enforcement activities. This 

information could also be useful to the Congress as it considers ways to 

improve the effectiveness of checkpoints and border security efforts. 

To better gauge the effects of border control efforts, we recommend that 

the Commissioner of Customs and Border Protection 

• develop additional performance measures for the Border Patrol for the 

productivity and effectiveness of interior checkpoints, such as 

apprehensions per agent work year and cost per apprehension, and 

• include in CBP’s Performance and Annual Report data and analysis 

provided by the additional performance measures on the performance 

of interior checkpoints and what might be done to improve their 

effectiveness. 

We requested comments on a draft of this report from the Secretary of 

Homeland Security. In its response, DHS said the report is factually 

correct, agreed with our recommendations, and stated that CBP is taking 

steps to implement them. With regard to our first recommendation, that 

Recommendations for 

Executive Action 

Agency Comments 
Page 48 GAO-05-435 Border Patrol 

the Commissioner of Customs and Border Protection develop 

performance measures for the Border Patrol in addition to its traditional 

ones, for the productivity and effectiveness of interior checkpoints, DHS 

stated that CBP is in the process of developing such measures for the 

Border Patrol for fiscal year 2006 and that one or more of the performance 

measures will gauge the effectiveness of checkpoints. DHS stated that 

CBP will consider our suggestions when developing these measures. With 

regard to our second recommendation, that CBP include in its 

Performance and Annual Report data and analysis provided by the 

additional performance measures on the performance of interior 

checkpoints, and what might be done to improve their effectiveness, DHS 

stated that once the performance measures for fiscal year 2006 for the 

Border Patrol are implemented and the data are tracked, CBP will publish 

the information in its Performance and Annual Report. 

DHS’s comments are reprinted in appendix VI. DHS also offered technical 

comments, which we considered and incorporated where appropriate. 

We are sending copies of this report to the Secretary of the Department of 

Homeland Security and interested congressional committees. We will also 

make copies available to others upon request. In addition, the report will 

be available at no charge on GAO’s Web site at http://www.gao.gov. 

If you or your staff have any questions about this report, please contact me 

at (202) 512-8777 or StanaR@gao.gov. Contact points for our Office of 

Congressional Relations and Public Affairs may be found on the last page 

of this report. GAO staff who made key contributions to this report are 

listed in appendix VII. 

Richard M. Stana 

Director, Homeland Security 

 and Justice Issues 
Appendix I: Scope and Methodology 

Page 49 GAO-05-435 Border Patrol 

To address our objectives, we examined and analyzed Border Patrol 

documents, reports, manuals, and guidance concerning border strategy 

and checkpoint operations. We interviewed cognizant Border Patrol 

officials at Washington, D.C. headquarters, officials in four sector offices, 

and personnel at selected permanent and tactical checkpoints. We visited 

sector headquarters, stations, and interior traffic checkpoints in four 

Border Patrol sectors—San Diego, California and Tucson, Arizona, and 

two in southeastern Texas, Laredo and McAllen. In total, we visited three 

sector headquarter offices, seven stations, five permanent checkpoints, 

and three tactical checkpoints. Sector offices and interior checkpoints we 

visited had one or more of the following characteristics: 

• offices that oversee permanent or tactical checkpoints, or both, to 

obtain information about both types, 

• permanent, nonpermanent, and tactical checkpoints with high, medium 

or low vehicular traffic volume, 

• permanent, nonpermanent, and tactical checkpoints with high, medium 

or low estimated smuggling volume (either aliens or contraband, or 

both), and 

• checkpoints that varied in terrain, with some situated with little 

peripheral area to evade the checkpoint and others situated so that 

patrols must be set up to prevent end runs. 

We visited and observed operations at the following Border Patrol sectors, 

which were selected to provide a range in type and size of operation: 

• Border Patrol stations and checkpoints in the Tucson, Arizona, sector 

where only nonpermanent checkpoints are permitted under current 

law, and because that sector has the most annual apprehensions of 

illegal immigrants. Also, we wanted to compare the operations of the 

Tucson sector interior checkpoints with the operations of tactical and 

permanent ones elsewhere. 

• Permanent and tactical checkpoints in the San Diego, California, sector 

because it contains two permanent ones with high volume—Temecula 

and San Clemente—and two requesters asked that these be included in 

a broader study of the effectiveness of all interior traffic checkpoints. 

• Permanent checkpoints in Texas at Falfurrias and Hebbronville, and on 

I-35, north of Laredo, as well as Border Patrol stations in Falfurrias and 

Hebbronville. The former is in the McAllen sector, while the latter is in 

the Laredo sector. 

Appendix I: Scope and Methodology 
Appendix I: Scope and Methodology 

Page 50 GAO-05-435 Border Patrol 

• Ports of entry at San Diego, California; Douglas, Arizona; and Laredo, 

Texas. We did so in order to better understand the differences 

between the operations of these ports of entry at the international 

border and the operations of the interior traffic checkpoints. 

Via helicopter, we observed the terrain and Border Patrol activities along a 

60-mile section of the international border, from San Diego inland and 

along approximately 200 miles of the border in the Tucson sector, from 

Ajo to Douglas, Arizona. 

The four sectors we visited were selected to provide a substantial range in 

the size and types of interior checkpoint operations; estimated volume of 

illegal annual immigration; volume of vehicular traffic transiting 

checkpoints; topography and density of road networks; presence or 

absence of large urban areas on or near the border, both on the U.S. and 

Mexican sides; and types of checkpoints (permanent, nonpermanent, and 

tactical). As we were told by the Border Patrol in deciding which sectors 

and checkpoints to visit, and as we found during our site visits, these four 

sectors contained a wide variety of operating conditions. For example, the 

San Diego sector’s permanent checkpoint near San Clemente on I-5 has 

the highest volume of average daily vehicle traffic among the Border 

Patrol’s 33 permanent checkpoints on the southwest border, while those 

north of Laredo, Texas, and at Falfurrias, Texas, average daily traffic 

volume about one-tenth that amount. Some of the tactical checkpoints we 

visited have average daily traffic volume that is only about one-hundredth 

that of San Clemente/I-5—that is, 1,500 vehicles or less daily, according to 

the Border Patrol and based on our observations during site visits. 

Similarly, there were substantial variations in the estimated numbers of 

illegal immigrants entering these sectors over the last several years, and 

wide differences in topography, with some being comparatively 

mountainous and others being comparatively flat. The Laredo and 

McAllen sectors have the Rio Grande as a natural barrier during the winter 

months to illegal immigration, while the Tucson sector has a flat desert at 

the border that is easily crossed. Some sectors have permanent 

checkpoints, such as at Temecula, California, that must be supplemented 

with tactical checkpoints, because of substantial secondary road networks 

around the permanent checkpoint. Others, such as McAllen, have no 

alternative secondary roads available to evade the permanent checkpoints 

on the limited north-south highways. Some sectors, such as San Diego and 

Laredo, have large U.S. and Mexican urban areas on or very near the 

international border, while others, such as Tucson, have only a few much 
Appendix I: Scope and Methodology 

Page 51 GAO-05-435 Border Patrol 

smaller cities on either side at the border.1 In choosing these sectors, 

which are located in three of the four southwest border states (California, 

Arizona and Texas, but not New Mexico) we sought and found a wide 

range of conditions that appear to reasonably represent the range of 

operating conditions faced by the Border Patrol across the Southwest. 

However, it is also the case that we were unable to observe all operating 

conditions at all times and that the conditions we describe are therefore 

based on available documentation and observations at our site visits only. 

We also interviewed selected officials in communities near some of the 

interior checkpoints, including local law enforcement and community 

officials, selected community leaders, citizens, and owners of local 

businesses. These included the communities of Temecula, California; 

Nogales, Arizona; Laredo, Texas, and the small town of Tubac, between 

Nogales and Tucson, Arizona. Because these places and persons were 

selected using a nonprobabilistic method, the results from our site visits 

cannot be generalized to other locations, checkpoints, local officials, or 

citizens. 

We contacted organizations that could be expected to monitor traffic 

congestion as part of their work, including the Automobile Club of 

Southern California, the American Trucking Associations, the California 

Department of Transportation, and the California Highway Patrol. We 

asked these organizations for reports, studies, or information on traffic 

congestion at selected interior traffic checkpoints we had visited, in 

particular those with high daily vehicle volume. 

To assess the reliability of the Border Patrol’s data on apprehensions, 

contraband seizures, and work hours, we talked with agency officials at 

both Washington, D.C., headquarters and some Border Patrol stations in 

the field about data quality control procedures, including methods by 

which data are checked and reviewed internally for accuracy and 

consistency. We also obtained and reviewed relevant documentation. We 

 1

For example, according to the U.S. Census, the city of San Diego, California, had an 

estimated population of 1.26 million in 2004, while San Diego County had an estimated 

population of 2.9 million in 2004. The city of Tijuana, Mexico, on the Mexican side of the 

border from San Diego, had an estimated population in 2000 of 1.2 million. In contrast, the 

city of Nogales, Arizona, which is located on the border with Mexico in the Tucson sector, 

had an estimated population of 21,000, and the county in which it is located had an 

estimated 41,000. Directly opposite Nogales, Arizona, the city of Nogales, Mexico, had an 

estimated population of 159,000 in 2000. The Mexican city of Nuevo Laredo, opposite the 

city of Laredo, Texas, had an estimated population of more than 650,000. 
Appendix I: Scope and Methodology 

Page 52 GAO-05-435 Border Patrol 

determined the data on apprehensions, contraband seizures, and work 

hours were sufficiently reliable for the purposes of this report. However, 

we agreed with Border Patrol officials that the data on costs of 

checkpoints were not sufficiently reliable to be used. 

To determine whether available Border Patrol data could be used to 

measure the performance of interior checkpoints compared with the 

performance of operations on the border (line patrol and line watch), both 

within and among Border Patrol sectors, we developed two measures of 

performance—apprehensions per agent work year and cost of 

apprehensions per agent work year. We chose to do this because the 

Border Patrol uses only traditional law enforcement measures to report on 

its performance, including apprehensions and amount and type of 

contraband seized. These are not assessed relative to the inputs (agent 

labor, overhead costs) that went into achieving them and therefore do not 

provide a guide on how to better allocate agency resources. 

To develop our first performance measure, apprehensions per agent work 

year, we obtained data from the Border Patrol for each of the four sectors 

we visited on the total number of agent work hours recorded as charged 

by agents who work at interior checkpoint operations, and for line watch 

and line patrol. (Line watch and line patrol operate very closely together 

on the border, and data are not recorded separately for them by the 

Border Patrol.) We were unable to perform an apprehensions per agent 

work year analysis for permanent or tactical checkpoints because data on 

agent hours charged to individual checkpoints are not recorded. That is, 

while work records are kept for hours charged by agents at interior 

checkpoints, the records do not distinguish between hours charged at 

permanent checkpoints versus those charged to tactical checkpoints in the 

same sector. 

Using the data charged to interior checkpoints and line watch/line patrol 

for each sector, we then divided these total hours by 2,080, which is the 

total number of hours in a standard work year of 52 weeks, and 40 work 

hours per week. (The Border Patrol work year is the same as that of the 

rest of the U.S. government.) The total agent work hours at checkpoints in 

a given sector, divided by 2,080, produced a data point that we called agent 

work years. Thus, if 2,080,000 hours were charged, the work year total 

would have been 1,000 work years—2,080,000 divided by 2,080. 

To calculate what we term apprehensions per agent work, we then took 

the data we had obtained on the number of apprehensions that occurred at 

interior checkpoints in each sector in a given fiscal year and divided that 
Appendix I: Scope and Methodology 

Page 53 GAO-05-435 Border Patrol 

number by the agent work year calculation. For example, if 10,000 

apprehensions occurred at interior checkpoints in a sector, and 2,000 

agent work years had been recorded as having been worked at those 

checkpoints, the apprehensions per agent work year were 5 (10,000 

apprehensions divided by 2,000 work years). Of course, this did not 

include the work of support personnel that contribute indirectly to the 

outcome of apprehensions. 

Our second measure was cost per apprehension, with apprehension 

actually being apprehension per work year, to control for the known input 

of agent work years. 

We chose this measure because a question that is frequently, if not almost 

universally, asked about government programs, is, “What is known about 

their cost effectiveness?”2

 One potential measure of such cost 

effectiveness for the Border Patrol would be how much did it cost to 

apprehend a single person in one sector, compared with other sectors? 

While this measure and others should not be taken in isolation as further 

guides to management decisions, knowledge of the basic costs of an 

agency’s key outcomes (such as apprehensions of illegal entrants) per unit 

of input (agent labor costs) can be part of the basis for improved 

allocation of resources. Of course, it would be even better if the full costs 

of all the inputs were known, such as infrastructure overhead, but these 

were not available. Therefore, we used data that were available as a 

method of illustrating how cost effectiveness measures could be more 

fully developed by the Border Patrol. 

To calculate cost per apprehension per agent work year, we divided the 

outputs by the inputs—in this case, the data on apprehensions per work 

year (e.g., 521 in Tucson in fiscal year 2001) divided by the average cost of 

an agent work year in fiscal year 2004, which the Border Patrol stated was 

$53,000, or the nationwide average for the GS-11, step 2, rank. This was 

described as the national average for Border Patrol agents; of course, it is 

an average for all agents, and does not reflect variations in cost of living 

 2

See, for example, GAO, 21st Century Challenges: Reexamining the Base of the Federal 

Government, GAO-05-325SP, (Washington, D.C.: Feb. 2005) p.15. Cost-effectiveness may 

be defined as achievement of a particular objective at the least cost. A cost-effectiveness 

approach is useful where there is a specific required outcome but that outcome cannot be 

quantified in monetary terms whereas costs can be estimated. Average cost is consistent 

with information for Border Patrol checkpoints, where the costs of labor (inputs) are 

available, and one of the outcomes, apprehensions, is not readily quantifiable in monetary 

terms. 
Appendix I: Scope and Methodology 

Page 54 GAO-05-435 Border Patrol 

adjustments, or for the true wider range of all Border Patrol salaries. We 

used the $53,000 average work year cost for all calculations for the period 

covering fiscal years 2001-2004 and did not adjust the work year cost for 

inflation. Our goal was again to show what the approximate cost per 

apprehension had been and how this measure could serve as a resource 

allocation tool, along with other information and data. 

We conducted our work from September 2004 to May 2005 in accordance 

with generally accepted government auditing standards. 
Appendix II: San Diego Sector Profile 

Page 55 GAO-05-435 Border Patrol 

The San Diego sector’s area of responsibility includes all of San Diego 

County and substantial portions of Orange and Riverside counties in 

California, covering more than 7,000 square miles and 60 miles of 

international border with Mexico. The San Diego sector encompasses 

coastal beaches and expansive mesas to coastal and inland mountains, 

rugged canyons, and high desert. Over half of the border in this sector 

consists of mountains, but there are also lesser amounts of rolling 

brushland, urban hilly terrain, canyons, farmland, flat desert, and flat 

urban terrain. Directly to the south of San Diego lie the Mexican cities of 

Tijuana and Tecate, Baja California—with a combined population of more 

than 2 million. For decades, this area was the preferred corridor for illegal 

immigration because of the highly populated neighborhoods north and 

south of the border. 

At the time of our September and December 2004 visits, the sector was 

headed by a chief patrol agent, had seven Border Patrol stations, and 1,634 

agents on duty. The sector used four-wheel-drive vehicles, police sedans, 

and vans to patrol between two parallel fences that were constructed 

along the border, stretching about 16 miles inland from the Pacific Ocean. 

In addition, the sector uses all-terrain vehicles (ATVs), helicopters, 

mountain bikes, and horses to patrol border areas. Seismic sensors are 

also used to identify where smugglers and illegal aliens are attempting to 

cross the border between the official ports of entry. 

The sector has 4 permanent interior traffic checkpoints and up to 11 

tactical checkpoints, which are operated on an as-needed basis (see fig. 

10). The two busiest permanent checkpoints in the sector are the ones 

located (1) on northbound I-5, south of San Clemente, about 68 miles from 

the border, and (2) on northbound I-15, near Temecula, also located about 

68 miles from the border. 

Most of the tactical checkpoints in the San Diego sector are operated by 

the Temecula station, which can field up to 8 tactical checkpoints located 

on a network of secondary state highways leading roughly northwest from 

the eastern San Diego area toward Los Angeles, and paralleling or 

intersecting the major I-15 interstate highway. According to Border Patrol 

officials, secondary roads make it possible for smugglers and illegal aliens 

to try to circumvent the I-15 Temecula checkpoint by taking side roads, 

unlike the San Clemente I-5 checkpoint, which has no surrounding 

secondary roads. Figure 10 shows the approximate location of the 

permanent checkpoints, on I-5 (San Clemente) and on I-15 (Temecula), as 

Appendix II: San Diego Sector Profile 

Geography of the Sector 

Organizational Structure of 

the Sector 
Appendix II: San Diego Sector Profile 

Page 56 GAO-05-435 Border Patrol 

well as some of the approximate locations used for tactical checkpoints, 

not all of which operate simultaneously. 

Figure 10: Road Infrastructure and Checkpoints in the San Diego Sector 

San Diego, CA

I-5

I-15

State Hwy 79

I-5

I-405

R3

I-8

I-8 West

Hwy 94

Mexico

802

Oak Grove

I-15

I-10

Hwy 76

Old Hwy

395 De Luz Rd.

Sandia

Creek Rd

San Clemente, CA

Los Angeles, CA

I-15

Temecula, CA Palm Springs, CA

Lake Henshaw

I-8 East

Old Hwy 80 West

San Diego Sector

El Centro Sector

Scissors Crossing

Hwy 74 & 371 Junction

Permanent checkpoints

Tactical checkpoints

Source: Border Patrol.
Appendix II: San Diego Sector Profile 

Page 57 GAO-05-435 Border Patrol 

We observed that the operations and physical layout of the two permanent 

checkpoints at San Clemente and Temecula were largely similar, and 

although the local geography differs somewhat, both checkpoints are 

situated at locations with high surrounding hills or other barriers (e.g., the 

ocean at the I-5 checkpoint), making it difficult to simply drive around the 

checkpoints. 

The I-5 checkpoint south of San Clemente has four traffic lanes, and 

Border Patrol agents stand between the lanes to screen traffic (see fig. 

11). Trucks pass through the adjoining weigh station, where they too are 

screened. 

Figure 11: Permanent Checkpoint on I-5, South of San Clemente 

The I-15 checkpoint near Temecula is similar to the one south of San 

Clemente, in terms of the Border Patrol agents having to monitor multiple 

lanes of traffic on a very busy highway. A major difference is that 

secondary roads south of the checkpoint offer alternative routes for 

persons to try to evade the I-15 Temecula checkpoint. 

Overview of Checkpoint 

Operations 

Source: GAO.
Appendix II: San Diego Sector Profile 

Page 58 GAO-05-435 Border Patrol 

According to Border Patrol officials, it is difficult for smugglers and illegal 

aliens to avoid the San Clemente I-5 traffic checkpoint because it is 

located in a physically constricted area between high hills on the right 

(facing north) and the ocean on the left, with no readily accessible side 

roads for miles prior to the checkpoint, because the Marine Corps’ Camp 

Pendleton borders it on the east. To circumvent the checkpoint, 

smugglers and illegal aliens must either go through a state park, where 

there are state park police, or through the hilly terrain of Camp Pendleton, 

where there are military police, according to the Border Patrol officials. 

Vehicles are observable for at least a mile south from cameras at the 

checkpoint, so that those attempting to improperly enter Camp Pendleton 

would be visible to the Border Patrol. 

Figure 12 shows an aerial photo of the I-5 checkpoint, with the hills in 

Camp Pendleton on the side of the checkpoint area to the upper right, and 

the ocean to the lower left of the checkpoint, making evasions of the 

checkpoint difficult. 

Figure 12: Aerial Photo of Checkpoint on I-5 South of San Clemente 

As of November 2004, the San Clemente station was staffed with a patrolagent-in-charge and approximately 100 Border Patrol agents. The 

Source: TerraServer USA Web site.

Checkpoint
Appendix II: San Diego Sector Profile 

Page 59 GAO-05-435 Border Patrol 

Temecula station was also staffed by a patrol-agent-in-charge and had 

approximately 127 agents. 

During our visit to the I-5 checkpoint, we observed agents performing 

traffic checks (i.e., screening vehicles) by staffing positions on the 

highway. We observed two agents standing between the lanes of the 

northbound I-5 traffic; each was responsible for screening vehicles that 

approached him or her. 

We were told that agents look for visual clues that could indicate drug or 

alien smuggling, as occurred in an incident we observed. During our visit, 

an agent told us that on the basis of such visual clues, he sent a vehicle to 

secondary inspection, where all passengers were later identified as illegal 

aliens. 

In another lane, closest to the center of the freeway, was a Pre-Enrolled 

Access Lane (PAL) which permitted vehicles to use an electronic 

transponder to move through more quickly than the normal traffic lanes. 

(Obtaining a transponder requires passing a background investigation; San 

Clemente is the only U.S. checkpoint with such a lane.) However, an agent 

was also positioned at the PAL lane, and during the period we were there, 

a vehicle that attempted to go through it without a transponder was 

ordered into secondary inspection, where it was determined that the 

occupants were illegal aliens. 

The I-5 checkpoint also performs checks on buses, which are to stop at the 

checkpoint, and on trucks, which are to transit the adjoining weigh 

station. The Border Patrol also screens trucks at that point, at times using 

the Vehicle and Cargo Inspection System (VACIS) machines, which use 

gamma-ray technology to examine the contents of vehicles. 

At the checkpoints, all suspected smugglers or illegal aliens are 

fingerprinted using the Automated Biometric Identification system and a 

law enforcement check is run on their fingerprints through the FBI’s 

Integrated Automated Fingerprint Identification System (IAFIS). If 

persons are determined to be undocumented aliens or are wanted for 

other offenses, detention facilities are available at the checkpoints. 

Border Patrol officials said that having the ability to perform fingerprint 

and law enforcement checks at the checkpoints enables them to quickly 

determine if detained persons are illegal aliens or have outstanding 

criminal complaints pending against them. Border Patrol officials told us 

that they had been conducting a project to identify the numbers of illegal 
Appendix II: San Diego Sector Profile 

Page 60 GAO-05-435 Border Patrol 

aliens with criminal records that had been apprehended in areas around 

the Temecula and San Clemente checkpoints. For example, after 

matching fingerprints with IAFIS during a 6-week period from August to 

September 2004, they found that 157 illegal aliens with criminal records 

had been apprehended by Temecula Border Patrol agents. These illegal 

aliens had criminal records that included assault, burglary, and 

immigration offenses. Overall, during the 6-week period, 28 percent of 

Temecula’s and 22 percent of San Clemente’s apprehensions were illegal 

aliens with criminal records. 

The Border Patrol regards the I-5 and I-15 checkpoints as 24-hour 

checkpoints, closing them generally only for safety reasons. However, as 

we observed when we visited the two checkpoints, heavy traffic volume 

may preclude screening every northbound vehicle. As noted above, the I-5 

checkpoint south of San Clemente is the busiest interior traffic checkpoint 

in the nation, with approximately 144,000 vehicles passing through daily, 

while the Temecula I-15 checkpoint ranks second, with approximately 

122,000 vehicles daily. However, as we observed, and as San Clemente 

and Temecula checkpoint officials told us, when traffic backs up, the 

traffic checks are suspended and traffic is “flushed” through the 

checkpoint. 

Agents said that they know from experience how long a wait period traffic 

backups are likely to produce, and that they keep a close watch on how 

long the line has become. During our visit, we observed that Border Patrol 

agents monitored traffic and took action to avoid creating major traffic 

delays at these checkpoints. 

Since the Border Patrol agents may suspend their operations to avoid 

creating lengthy traffic delays, actual time that the agents stand out on the 

highway lanes and visually inspect traffic varies. Checkpoint records 

showed that at the I-5 checkpoint south of San Clemente, traffic was 

screened only about 36 percent of the time in fiscal year 2004, a reduction 

from about 57 percent in fiscal year 2003 and about 63 percent in fiscal 

year 2002. Temecula checkpoint traffic was screened only about 42 

percent of the time in fiscal year 2004, down from about 63 percent of the 

time in fiscal year 2003. Border Patrol officials attributed these declines to 

a combination of insufficient staffing levels at the stations and the need to 

avoid imposing long traffic waits on the public. According to Temecula 

station officials at the time of our September 2004 visit, they had received 

no complaints for at least several months about traffic delays. 

Traffic Impact 
Appendix II: San Diego Sector Profile 

Page 61 GAO-05-435 Border Patrol 

We observed that the permanent checkpoints at San Clemente and 

Temecula had a range of capabilities to monitor and inspect vehicles and 

their occupants. These included 

• concrete side aprons off the highway to permit more intensive 

secondary inspections, 

• cages and shade for canines, 

• surveillance cameras for monitoring activities at the checkpoint and 

traffic backup, 

• computers with hardline communications, 

• detention facilities for holding smugglers and illegal aliens, and 

• concrete side aprons with their own traffic lane to permit trucks to line 

up for VACIS gamma-ray inspections. 

In addition to manning the permanent checkpoints, the Border Patrol 

routinely sets up tactical checkpoints to reduce the chances of persons 

evading the permanent ones by using secondary roads. In particular, the 

Temecula checkpoint has eight locations where tactical checkpoints are 

established as needed based on intelligence on illegal immigration or 

related activity. We observed a tactical checkpoint on Sandia Creek road, 

south and west of the I-15 checkpoint, in a back hill rural area that had 

little traffic, but where the secondary road network could allow for 

evading checkpoints on the main highway (see fig. 13). At this tactical 

checkpoint, agents stopped each vehicle and talked to drivers and 

passengers; in contrast, at permanent checkpoints with heavy traffic 

volume, most vehicles are not stopped but are observed as they move 

slowly through the checkpoint lanes. 

Checkpoint Capabilities 

Tactical Checkpoints 

Supplement Permanent 

Ones 
Appendix II: San Diego Sector Profile 

Page 62 GAO-05-435 Border Patrol 

Figure 13: Tactical Checkpoint at Sandia Creek Road, Near Temecula, California 

Source: GAO.
Appendix III: Tucson Sector Profile 

Page 63 GAO-05-435 Border Patrol 

The Tucson, Arizona, sector’s area of responsibility runs 261 miles along 

the U.S.-Mexico border from New Mexico to the Yuma County, Arizona, 

line; it is 90,530 square miles in area. The sector encompasses national 

parkland and parts of the Tohono O’odham Indian reservation, and its 

environment is like that of much of the southwest border—the terrain is 

inhospitable, consisting of mountains, flat desert, rolling brushland, and 

canyons. Summer temperatures can reach an average daily high of 100 to 

110 degrees, and lack of shade for vast stretches of the border and inland 

areas can pose severe health hazards to those attempting to walk across 

the area. 

Most of the border in this sector is delineated by cattle fences and border 

markers, with little effective fencing of any kind, according to Border 

Patrol officials. Cattle fences can prevent cattle from crossing the border, 

but they are not designed or intended to prevent people from doing so, as 

they are essentially strands of wire with large gaps between them and are 

easily pushed apart, according to the officials. Agents patrol the border by 

truck, aircraft, horseback, ATVs, and bicycles and on foot; maintain traffic 

checkpoints along highways leading from border areas; and conduct 

antismuggling investigations. 

At the time of our October 2004 visit, the sector was headed by a chief 

patrol agent and staffed by 2,100 Border Patrol agents deployed 

throughout the sector from eight Border Patrol stations. 

Border Patrol operations in the Tucson sector have been the subject of 

legislative direction since fiscal year 1999; this direction applied to no 

other Border Patrol sector. For fiscal years 1999-2004, annual 

appropriations acts made no funds “available for the site acquisition, 

design, or construction” of any Border Patrol checkpoint in the Tucson 

sector.1

 Since the Tucson sector had no permanent checkpoints in fiscal 

 1

Omnibus Consolidated and Emergency Supplemental Appropriations Act, 1999, P.L. 105-

277 (1998); Consolidated Appropriations Act, 2000, P.L. 106-113 (1999); Appropriations for 

the District of Columbia, 2001, P.L. 106-553 (2000); Departments of Commerce, Justice, and 

State, the Judiciary, and Related Agencies Appropriations Act, 2002, P.L. 107-77 (2001); 

Consolidated Appropriations Resolution, 2003, P.L. 108-7 (2003); Department of Homeland 

Security Appropriations Act, 2004, P.L. 108-90 (2003); and Department of Homeland 

Security Appropriations Act, 2005, P.L. 108-334 (2004). 

Appendix III: Tucson Sector Profile 

Geography and 

Organization of the Sector 

Overview of Sector 

Operations 
Appendix III: Tucson Sector Profile 

Page 64 GAO-05-435 Border Patrol 

year 1999 (or before), the effect of this legislative language was that no 

permanent checkpoints could be planned or constructed in this sector.2

To comply with the congressional ban on funding for permanent 

checkpoints, and the congressional requirement to relocate checkpoints 

after a specified period of days, the Border Patrol told us that the sector 

maintains what we term nonpermanent checkpoints that, when open, are 

generally at the same locations, with the exception of one on I-19, from 

June 2002 through fiscal year 2004, and another on state highway 83. On I19, a major north-south interstate highway that runs from Nogales on the 

border north to Tucson, about 70 miles away, nonpermanent checkpoints 

were alternated between KP 42 and KP 25, 17 kilometers further south, 

from June 2002 through the end of fiscal year 2004. Starting in fiscal year 

2005, the Border Patrol kept the checkpoint at the KP 42 location to 

preclude illegal entrants from taking advantage of its being moved 

southward to KP 25, as had regularly occurred. The checkpoint is kept 

open for 14 days, closed for 8 hours, then reopened for 14 days, and so 

forth, according to the Border Patrol. The Border Patrol states that it 

believes that this schedule conforms to the fiscal year 2005 legislative 

language requiring that Tucson sector checkpoints relocate “at least an 

average of once every 14 days.” Other checkpoints in the sector have been 

opened and closed on varying schedules in fiscal year 2005, but those 

schedules also conform to the law, according to the Border Patrol. To 

support these nonpermanent checkpoints, the Tucson sector operates 

tactical checkpoints periodically, as occurs in other sectors with 

permanent checkpoints. The tactical checkpoints function the same way 

as tactical ones in other sectors with permanent checkpoints. 

Figure 14 shows the sector and the approximate locations at which 

nonpermanent checkpoints may be located when open. 

 2

According to the Border Patrol, it used a combination of roving patrols and temporary 

checkpoints that remained at the same location for long periods but did not have 

permanent infrastructure. 
Appendix III: Tucson Sector Profile 

Page 65 GAO-05-435 Border Patrol 

Figure 14: Road Infrastructure and Checkpoints in the Tucson Sector 

According to the Border Patrol, it also alternates among three sites for 

checkpoints on state highway 83. (The approximate locations are shown 

as 83C MP54, 83C, and 82 in fig. 14). Because of safety issues, the 

nonpermanent checkpoints designated as SR 90, 80C and highway 191 do 

not have alternative sites. They are kept open for the legislatively 

permitted length of time, and then closed, according to the Border Patrol. 

Another checkpoint is open and closed about the same hours as a port of 

entry south of it on the border. However, the Border Patrol monitors 

sector night traffic with various means, such as roving patrols; these are 

sufficient, they told us, given the very light traffic in the sector at night. 

Phoenix, AZ

Tucson Sector

El Paso Sector

Yuma Sector

I-10 I-19

Hwy 191

Hwy 70

Hwy 191

State Hwy 80

State Hwy 191

State Hwy 86

State Hwy 85

State Hwy 286

Hwy 60

80C

Nogales, AZ Naco, AZ

Douglas

Mexico , AZ

82

83C

SR 85

I-8

83C MP54

SR 90

KP 42

KP 25

Tucson, AZ

Lukeville, AZ

Nonpermanent checkpoints

Source: Border Patrol.
Appendix III: Tucson Sector Profile 

Page 66 GAO-05-435 Border Patrol 

We observed the operations of the nonpermanent checkpoint on I-19, the 

north-south interstate highway that runs from Nogales on the border north 

to Tucson, about 70 miles away. According to Border Patrol officials, only 

limited routes are available to circumvent the I-19 checkpoint, primarily by 

driving or walking across countryside that can make smugglers or aliens 

relatively visible, because of vehicles raising dust in their wake. In fiscal 

year 2003, an average of over 15,000 vehicles passed through the I-19 

checkpoint daily, including many commercial trucks, especially during 

produce season, according to the officials. 

The I-19 nonpermanent checkpoint consisted of a trailer, portable 

generators, water, and rest room facilities that were towed in; traffic 

warning signs; and orange traffic cones to designate the checkpoint area 

and to slow vehicles down to be inspected. At the time of our visit, the I19 checkpoint was located next to an overpass to provide some protection 

from the elements, since there was no canopy as is typically found at 

permanent checkpoints we visited in other sectors. Border Patrol officials 

also said that only two locations along I-19 are appropriate for checkpoint 

operations because of space and safety considerations. From June 2002 

through the end of fiscal year 2004, the I-19 checkpoint was alternated 

between these two locations, at KP 42 and KP 25, relocating every 7 days. 

During fiscal year 2005, the checkpoint location has been maintained only 

at the northern location, as noted above, and is open for 14 days, then 

closed for 8 hours, and then reopened for 14 days. 

At the I-19 checkpoint locations, the Border Patrol has three lanes of 

northbound traffic to screen—two highway lanes and an off-ramp. The 

operation, consisting of Border Patrol agents and canines, was run out of a 

trailer, with a small detention room inside it, and a stand-alone computer 

not connected externally. There was no hardwired computer access to 

databases to check fingerprints or to validate identities through other law 

enforcement databases. Therefore, according to Border Patrol agents, 

they can process some reports on the computer but have to save 

information to a diskette and take it back to the station for further 

processing. Similarly, processing and fingerprinting of suspects must wait 

until the suspects are transported to a Border Patrol station with 

hardwired computers. 

During summer months, we were told, the temperature can reach about 

130 degrees on the heated tarmac of the highway; as a result, canine 

performance and endurance are limited. 

Checkpoint Operations 
Appendix III: Tucson Sector Profile 

Page 67 GAO-05-435 Border Patrol 

According to the Border Patrol, equipment that must be relocated when 

the I-19 and other checkpoints are moved includes a minimum of 3 light 

generator plants; 1 generator; 1 portable toilet; 20-100 traffic cones; and 5 

or more signs, showing “Stop,” “Checkpoint Ahead,” “Reduce Speed,” and 

similar warnings. In addition, the standard minimum deployment would 

be one processing trailer and detention area, two or more marked vehicles 

and a water trailer. 

The I-19 checkpoint at KP 42 had little area off-road to conduct secondary 

inspections, and that area consisted of dirt along the side of the highway. 

Border Patrol officials told us that to comply with legislative restrictions, 

they were unable to install anything that could be considered to create a 

permanent infrastructure, such as water lines, electricity, buried 

communication lines or towers, and buildings. Figure 15 shows the I-19 

nonpermanent checkpoint near KP 42. 

Figure 15: Tucson Sector Nonpermanent Checkpoint on I-19 near KP 42 

Source: GAO.
Appendix III: Tucson Sector Profile 

Page 68 GAO-05-435 Border Patrol 

We also observed the nonpermanent checkpoint on state highway 85, near 

Ajo, Arizona. According to Border Patrol officials, this checkpoint is 

located just south of where state highways 85 and 86 merge, both coming 

from the south, in order to ensure that all vehicles traveling north must go 

through the checkpoint. Only about 1,100 vehicles transit this checkpoint 

daily, we were told. As with the I-19 checkpoint, there were only limited 

portable equipment capabilities at the Ajo checkpoint. There was no 

overpass to provide shade. The Ajo checkpoint is shown in figure 16. 

Figure 16: Nonpermanent Checkpoint on State Highway 85 near Ajo, Arizona 

Checkpoint on State 

Highway 85 Near Ajo, 

Arizona 

Source: GAO.
Appendix IV: Laredo Sector Profile 

Page 69 GAO-05-435 Border Patrol 

The Laredo, Texas, Border Patrol sector covers 110,000 square miles, 116 

counties or parts of counties extending north to the Oklahoma border, and 

approximately 171 river miles of common border with Mexico. The 

sector’s eastern border is the McAllen sector, its southern border is the 

Rio Grande, and its western border is the Del Rio sector. The sector’s 

international border represents about 10.6 percent of the southwest 

border, and includes the International Falcon Reservoir, sometimes called 

Falcon Lake, a 120-square-mile body of water that was formed by damming 

the Rio Grande in 1953. The southwestern side of the lake is controlled by 

Mexico, the northeastern side by the United States, with the international 

border running down an imaginary line through the middle. 

The sector’s diverse economic base includes portions of the Rio Grande 

Valley, with large, privately owned cattle ranches, other agribusiness, and 

a large volume of goods from Mexico that are trucked through the Laredo 

ports of entry into the United States, and which are then stored in 

warehouses while awaiting inspection and transfer into trucks for 

transport to the rest of the United States. According to Border Patrol 

officials, Laredo is one of the busiest commercial ports of entry in the 

United States. The sector landscape generally consists of rolling 

brushland, reservoirs, farmland, and urban flatland, with the more rural 

sections being fairly flat but also having dense undergrowth that can 

impede persons such as smugglers or illegal aliens attempting to walk offroad, according to Border Patrol officials. 

At the time of our January 2005 visit, the sector was headed by a chief 

patrol agent and staffed with 981 Border Patrol agents, deployed 

throughout the sector from eight Border Patrol stations. The sector had 

ATVs, helicopters, fixed wing aircraft, and patrol boats; the last are used to 

patrol the International Falcon Reservoir. The patrol boats are not used 

for Rio Grande patrol, but jet skis are used for swift water river rescues, 

according to Border Patrol officials. Approximately 80 canines are also 

assigned to traffic screening operations at the sector’s checkpoints. 

The sector has five permanent checkpoints that screen traffic 24 hours a 

day, 7 days a week, generally closing only for safety reasons, and utilizes 

up to six tactical checkpoints that are opened on an as-needed basis, 

according to Border Patrol officials. We visited two permanent 

checkpoints in the sector, on two-lane state highway 351, in the vicinity of 

Hebbronville, and on I-35, the major north-south interstate highway 

leading to and from Laredo and San Antonio. We also visited the 

construction site of a new, replacement permanent checkpoint for the 

Appendix IV: Laredo Sector Profile 

Geography of the Sector 

Organizational Structure of 

the Laredo Sector 
Appendix IV: Laredo Sector Profile 

Page 70 GAO-05-435 Border Patrol 

existing one on I-35, about 10 miles north of the current location. That 

new checkpoint is scheduled to open in August 2005, according to Border 

Patrol officials. 

There are more secondary roads in the Laredo sector than in the 

neighboring McAllen sector; as a result, the Border Patrol maintains more 

permanent checkpoints and also utilizes tactical checkpoints. According 

to Border Patrol officials, tactical checkpoints are used during certain 

times of the year, depending on factors such as increases in traffic on 

secondary roads, and local, state, or national events being conducted in 

the area. The sector’s permanent and tactical checkpoints are strategically 

placed on roads and highways and at junctions that permit monitoring and 

inspection of vehicles leaving the border area, according to the officials 

(see fig. 17). 
Appendix IV: Laredo Sector Profile 

Page 71 GAO-05-435 Border Patrol 

Figure 17: Road Infrastructure and Checkpoints in the Laredo Sector 

Note: The location shown on highway 83 is a proposed checkpoint; therefore, there are five current 

permanent checkpoints. 

According to the Border Patrol, traffic checkpoint operations are generally 

supported by local ranchers, who permit the Border Patrol to enter their 

fenced property. The ranchers also permit the Border Patrol to place 

sensors at locations that could be favored by smugglers, according to 

Border Patrol officials. 

Laredo

State Hwy 285

U.S. Hwy 59

State Hwy 44

State Hwy 359

U.S. Hwy 83

I-35

New I-35

checkpoint

I-37

U.S. Hwy 277

U.S. Hwy 93

Permanent checkpoints

Tactical checkpoints

Source: Border Patrol.
Appendix IV: Laredo Sector Profile 

Page 72 GAO-05-435 Border Patrol 

We observed the operations of two permanent checkpoints in the Laredo 

sector; on I-35, about 15 miles north of Laredo, and another on state 

highway 359 between Falfurrias in the McAllen sector and Laredo. As was 

the case with other checkpoints we visited in this and the McAllen sector, 

the checkpoints had a tollbooth-like area with at least two traffic lanes, 

one reserved for passenger cars and trucks, and the other for commercial 

trucks and buses (see fig. 18). 

Figure 18: Permanent Checkpoint North of Laredo, Texas, on I-35 

At the time of our visit, the I-35 checkpoint was staffed with one 

supervisor, six agents, and canines. The facility consisted of a trailer that 

contained IAFIS fingerprinting equipment, three holding areas for 

apprehended illegal aliens, and video cameras (including infrared for 

nighttime use) to monitor activities in and around the checkpoint. Border 

Patrol agents told us that I-35 vehicle traffic wait time has not been more 

than 20 to 30 minutes, and generally takes place around 2:00 p.m. We 

observed a lift that could be used to inspect under vehicles, but did not 

observe trucks being examined by gamma ray equipment. We asked 

whether VACIS equipment was available to screen trucks with gamma ray 

Checkpoint Operations 

Source: GAO.
Appendix IV: Laredo Sector Profile 

Page 73 GAO-05-435 Border Patrol 

as we had seen at other checkpoints, and the agents told us that VACIS 

trucks were not permanently located at the checkpoint but are made 

available periodically by the official port of entry if they are requested. 

As was the case for checkpoints in the McAllen sector, those in the Laredo 

sector are directed to inspect every vehicle that is proceeding northward, 

according to Border Patrol officials. Because there are few north-south 

roads in the sector, an absence of secondary roads to go around the 

checkpoints, and manageable volume of traffic, it is possible to screen all 

vehicles transiting the checkpoints, according to Border Patrol officials. 

As we observed, each vehicle was sniffed by a canine, and occupants were 

questioned by a Border Patrol agent. We were told that the agents are able 

to process a vehicle on average in about 9 seconds. The checkpoint at I-35 

averages about 13,600 transiting vehicles daily, according to the Texas 

Department of Transportation; of these, about 36 percent are trucks. 

Border Patrol agents at the highway 359 checkpoint outside of 

Hebbronville (see fig. 19) told us that they had recently apprehended a 

number of “brush walkers,” illegal aliens who had been walking through 

the brush surrounding the checkpoint to evade apprehension at the 

checkpoint. The agents said that smugglers will drop off a load of aliens 

just short of the checkpoint so that they can attempt to walk around to a 

point where they would be picked up again. However, the agents said that 

it is very difficult terrain to traverse, even along ranch and pipeline trails, 

which are monitored by several means, including electronic surveillance. 

The agents further stated that local ranchers are very supportive of the 

Border Patrol activities in the area and have provided keys to their 

ranches for access when intrusions are detected, or when the ranchers 

themselves call to notify agents that suspected illegal aliens are on the 

property. Figures 19 and 20 show two checkpoints in the sector. 
Appendix IV: Laredo Sector Profile 

Page 74 GAO-05-435 Border Patrol 

Figure 19: Permanent Checkpoint on State Highway 359 Near Hebbronville, Texas 

Source: GAO.
Appendix IV: Laredo Sector Profile 

Page 75 GAO-05-435 Border Patrol 

Figure 20: Aerial View of Highway 359 Checkpoint, Texas 

The Laredo checkpoints we observed had a wide range of capabilities to 

screen vehicles and their occupants. These included 

• permanent tollboth-like structures that provide cover from the 

weather, including shade for agents and canines; 

• lifts to permit inspection of undersides of vehicles; 

• computers with hardwired communications and databases to permit 

investigation into those detained; 

• detention facilities; and 

• concrete side aprons with their own traffic lanes to permit trucks to 

line up with off highway room for inspections. 

As noted, a new I-35 checkpoint is scheduled to open in August 2005, 

about 10 miles north of the current location. Border Patrol officials told 

us that one major advantage of the new location is that it will not be within 

sight of warehouses or other structures, which they said currently provide 

cover for smugglers to observe the operations at the existing I-35 

checkpoint. The new checkpoint, which will cost about $12 million to 

Checkpoint Capabilities 

Source: Border Patrol.
Appendix IV: Laredo Sector Profile 

Page 76 GAO-05-435 Border Patrol 

construct, will be able to accommodate six lanes of vehicles, with separate 

lanes for passenger vehicles and trucks, along with a large area for 

inspecting and unloading trucks, if necessary (see fig. 21). 

Figure 21: Architectural Drawing of the New I-35, Texas, Permanent Checkpoint 

Source: Border Patrol.
Appendix V: McAllen Sector Profile 

Page 77 GAO-05-435 Border Patrol 

The McAllen, Texas, Border Patrol sector covers 18,584 square miles, 19 

counties, and approximately 316 river miles of common border with 

Mexico. According to Border Patrol officials, the sector’s area of 

responsibility runs from the mouth of the Rio Grande at the Gulf of Mexico 

to the Zapata/Starr county line, where it meets the Laredo sector. The 

sector’s international border represents about 9.4 percent of the southwest 

border; its southern edge follows the Rio Grande through Brownsville, 

emptying into the Gulf of Mexico. Large parts of the sector, which 

includes a portion of the Rio Grande Valley, are privately owned ranches, 

including the well-known King Ranch, which is approximately 800,000 

acres in size. 

Although the land in the sector is fairly flat, it receives sufficient 

precipitation to permit growth of dense sage, scrub brush, and cacti. This 

has created an inhospitable environment for persons such as smugglers or 

illegal aliens attempting to walk off-road, as the brush is so thick that it 

can actually block foot traffic or can severely injure persons trying to 

negotiate it, according to Border Patrol officials. 

Appendix V: McAllen Sector Profile 

Geography of the Sector 
Appendix V: McAllen Sector Profile 

Page 78 GAO-05-435 Border Patrol 

At the time of our February 2005 visit, the sector was headed by a chief 

patrol agent and staffed with 1,465 Border Patrol agents, deployed 

throughout the sector from nine Border Patrol stations. The sector had 

ATVs, helicopters, patrol boats, and fixed wing aircraft. The sector also 

utilizes bicycle patrols around the ports of entry and downtown areas, and 

video monitors and electronic sensors placed along the border to detect 

people or vehicles attempting to enter the country illegally. 

Only two major north-south highways in the sector lead away from the 

border: U.S. highways 281 and 77. The Border Patrol has permanent 

checkpoints on both, at Falfurrias and Sarita, respectively. Both 

checkpoints are approximately 80 miles inland from the international 

border and are roughly parallel to each other, although about 25 miles 

apart (see fig. 22). Border Patrol officials told us that the combination of 

only two north-south highways and the absence of secondary roads make 

it unnecessary to establish tactical checkpoints in support of the 

permanent ones. The checkpoints at Falfurrias and Sarita cannot be easily 

evaded by walking or driving around them, given the terrain, fenced 

private ranches, detection sensors, and lack of secondary roads, Border 

Patrol officials stated. 

Organizational Structure of 

the Sector 
Appendix V: McAllen Sector Profile 

Page 79 GAO-05-435 Border Patrol 

Figure 22: Road Infrastructure and Checkpoints in the McAllen, Texas Sector 

Sarita Gulf of Mexico

McAllen Sector

Laredo Sector

U.S. Hwy 281

U.S. Hwy 77

Mexico

San Antonio, TX

McAllen, TX

Falfurrias

Corpus Christi, TX

Permanent checkpoints

Source: Border Patrol.
Appendix V: McAllen Sector Profile 

Page 80 GAO-05-435 Border Patrol 

Much of the land near the Border Patrol checkpoints on U.S. highways 281 

and 77 is private ranch land that is both heavily fenced and actively 

patrolled by private security forces, according to Border Patrol officials. 

As in the Laredo sector, checkpoint operations are supported by the local 

ranchers, according to the Border Patrol, who permit the Border Patrol to 

enter their fenced property to apprehend illegal entrants. 

We observed the operations of the Falfurrias permanent checkpoint on 

U.S. highway 281, a major north-south highway that runs from McAllen on 

the border north toward San Antonio, Texas (see fig. 22). This checkpoint 

(and the one on U.S. highway 77, which we did not visit) had a tollboothlike area with at least two traffic lanes, one reserved for passenger cars 

and trucks, while the other is for commercial trucks and buses. At both 

checkpoints, Border Patrol agents are to stop and screen every vehicle 

that is proceeding northward. As we observed, each vehicle was sniffed 

by a canine, and its occupants were questioned by a Border Patrol agent. 

We also observed a bus being searched, after a canine got a “hit,” 

indicating possible drugs. The agents found three 30-pound packages of 

marijuana in the engine compartment. 

According to Border Patrol officials, the agents process a vehicle in about 

9 seconds and average about 14,900 vehicles—about 40 percent trucks—a 

day transiting the checkpoints. This volume of traffic allows for agents to 

stop and question occupants of each vehicle, compared with the 144,000 

vehicles daily going through the California checkpoint on I-5 south of San 

Clemente. 

There is little need to use tactical checkpoints in support of the permanent 

ones in the McAllen sector, according to Border Patrol officials, because a 

lack of secondary roads and geography that is not easily traversed force 

smugglers and illegal aliens to attempt to proceed through the checkpoints 

on U.S. highways 281 and 77. This situation is in contrast to the Tucson 

and San Diego sector operations, where tactical checkpoints on secondary 

roads are constantly being used to support the permanent checkpoints 

because of the many different routes leading away from the border that 

are available to smugglers and illegal aliens. 

The permanent checkpoints on U.S. highways 281 and 77 had a wide range 

of capabilities and facilities to screen vehicles and their occupants. These 

included 

Checkpoint Operations 

Checkpoint Capabilities 
Appendix V: McAllen Sector Profile 

Page 81 GAO-05-435 Border Patrol 

• permanent tollbooth-like structures that provide cover from the 

weather, including shade for agents and canines; 

• lifts to permit inspection of undersides of vehicles; 

• computers with hardwired communications and databases to provide 

identity checks; 

• detention facilities; and 

• concrete side aprons away from main traffic lanes that permit trucks to 

safely line up with sufficient room for a VACIS gamma-ray vehicle to 

pass over and inspect them. 

Figure 23 shows several photos of the checkpoint on U.S. highway 281, 

near Falfurrias, Texas. 
Appendix V: McAllen Sector Profile 

Page 82 GAO-05-435 Border Patrol 

Figure 23: Checkpoint Inspection Area, U.S. Highway 281, near Falfurrias, Texas 

Source: GAO.

Falfurrias Signage 

Trucks pulling over to apron area for 

VACIS inspection

VACIS truck passes x-ray arm over trucks 

waiting for processing

Shaded canine cages Computers linked to databases
Appendix VI: Comments from the Department 

of Homeland Security 

Page 83 GAO-05-435 Border Patrol 

Appendix VI: Comments from the 

Department of Homeland Security 
Appendix VI: Comments from the Department 

of Homeland Security 

Page 84 GAO-05-435 Border Patrol 
Appendix VII: GAO Contact and Staff 

Acknowledgments 

Page 85 GAO-05-435 Border Patrol 

Richard M. Stana (202) 512-8777 

In addition to the contact named above, Leo Barbour, Katherine Davis, 

Darryl W. Dutton, Ann H. Finley, Lemuel N. Jackson, James R. Russell, and 

Jonathan R. Tumin made key contributions to this report. 

Appendix VII: GAO Contact and Staff 

Acknowledgments 

GAO Contact 

Acknowledgments 

(440348) 
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