Border Security: Improvements Needed to Increase Vehicle Scanning at Land Ports of Entry

What GAO Found

U.S. Customs and Border Protection (CBP) uses non-intrusive inspection (NII) systems, such as X-ray machines, to inspect vehicles and travelers at land ports of entry (POE). As part of this process, CBP officers use large-scale NII systems to scan entire vehicles and their contents. These scans produce images that CBP officers review to help detect illegal drugs or other contraband. In 2020, to increase vehicle scans, CBP began deploying these systems to preprimary inspection areas-before a traveler is interviewed by a CBP officer. Previously, NII systems were generally used only when an officer determined that further inspection was required after the interview.

Non-Intrusive Inspection Systems Deployed in Preprimary Inspection Areas at Mission, Texas (left), and Laredo, Texas (right)

CBP uses performance data to help ensure large-scale NII systems are operational, but it has not defined all key performance parameters for NII systems. For one key parameter, CBP reports and uses data on the percentage of time that large-scale NII systems are available for operational use. However, CBP has not clearly defined or reported results for its other two key parameters related to inspection rate and examination of containers and cargo. For example, CBP's inspection rate parameter requires 100 percent inspection of high-risk commercial vehicles and container cargo, but CBP has not clearly defined the term "high risk" or the meaning of maintaining 100 percent inspection of targeted containers, cargo, and international mail. Clearly defining and reporting results for all of its key performance parameters would help CBP manage the NII program and inform future procurement decisions.

CBP has made progress deploying large-scale NII systems. As of February 2025, 52 of 153 planned systems were fully operational, nearly all at preprimary inspection areas. Deployments have cost more and taken longer than CBP estimated due to, for example, unexpected construction challenges.

Congress directed CBP to develop a plan to achieve 100 percent scanning of commercial and passenger vehicles and freight rail at land POEs using large-scale NII by 2027. CBP estimated that it would need 434 large-scale NII systems to achieve this goal at the northern and southwest borders-281 of which have not yet been procured, including 62 for the southwest border. However, CBP's plans for the southwest border omit systems to scan passenger vehicles at nine crossings, including three of its highest-traffic locations that account for nearly 40 percent of passenger vehicle traffic at the southwest border in fiscal year 2024. Without these crossings in its plan, CBP risks entry of many unscanned passenger vehicles, hampering its ability to prevent illegal drugs and other contraband from entering the United States.

Why GAO Did This Study

Since 2019, CBP has received over $2 billion that it has used to deploy additional NII systems to land POEs, which are a key drug smuggling route. This testimony summarizes a report GAO published in September 2025 in response to a request to review the implementation and effectiveness of CBP's NII program entitledLand Port Inspections: CBP Should Improve Performance Data and Deployment Plans for Scanning Systems. This testimony focuses on three areas: (1) how CBP assesses large-scale NII performance, (2) the status of large-scale NII system deployments, and (3) CBP's plans for future large-scale NII system deployments.

To inform that report, GAO analyzed NII program documentation, including inspection procedures, performance data, and deployment plans, and interviewed program officials. GAO also interviewed and observed CBP officers conducting inspections at land POEs where large-scale NII systems had been deployed in preprimary inspection areas.