What federal GAO and DHS analyses exist assessing the effectiveness of detection technology versus physical barriers along the Southwest border?
Executive summary
Congressional watchdog reports from the Government Accountability Office document multiple GAO analyses and DHS submissions that examine surveillance "technology" deployments and the construction/prioritization of physical barriers along the Southwest border, and consistently find progress in technology deployment but gaps in DHS’s evaluation of how technologies and barriers compare in effectiveness and cost [1][2][3].
1. What GAO has produced: catalogue and central findings
GAO has issued a series of reports and testimonies assessing DHS efforts to deploy and measure surveillance technologies and to build and prioritize physical barriers—key products include testimony and reports summarized in GAO-18-397T (a 2018 statement synthesizing three 2017 GAO reports) and focused reports such as GAO-18-119 on surveillance deployments and GAO-18-614 on barrier designs and prioritization, all of which document progress in deploying radars, sensors, and cameras while flagging shortcomings in DHS’s analyses and planning [2][1][3].
2. What GAO says about technology: deployment progress, data quality, and assessment gaps
GAO documents that U.S. Border Patrol has made measurable progress deploying a mix of radars, sensors, and cameras under plans such as the 2011 Arizona Technology Plan and the 2014 Southwest Border Technology Plan and that by October 2017 select technology deployments were completed in several sectors, but GAO repeatedly criticizes DHS and Border Patrol for weak data quality, incomplete guidance on asset-assist reporting, and insufficient evaluation of technology effectiveness across varied terrain [1][2][4].
3. What GAO says about physical barriers: prioritization, prototypes, and missing cost analysis
GAO’s reviews of CBP’s Border Wall System and prototype process show that CBP evaluated barrier designs and produced a prioritized list of segments, yet proceeded without key information—most notably failing to analyze segment-specific costs and lifecycle considerations—which led GAO to recommend that DHS include cost analyses and better documentation in future planning [5][3][6].
4. Direct GAO comparisons of “technology versus barriers”: limited analytic conclusions
While GAO has repeatedly asked DHS to better measure and attribute the contributions of tactical infrastructure and technology to “operational control,” GAO reports show DHS and CBP have not produced robust, cost‑effective evaluations directly comparing the effectiveness of detection technologies against physical barriers across the Southwest border; GAO specifically found CBP could not separately account for the impact of tactical infrastructure despite large investments and urged cost‑benefit and alternatives analysis [7][4][8].
5. DHS products and statutory plans examined by GAO: what DHS provided and where it fell short
DHS submitted Border Security Improvement Plans as required by Congress that describe intended mixes of personnel, barriers, and technology, but GAO’s assessments note missing elements—such as comprehensive implementation schedules, detailed analyses of alternatives, and performance metrics—leading GAO to caution that DHS’s submissions lacked the timely, comprehensive information Congress sought to support funding and oversight decisions [8][9].
6. The bottom line and reporting limits: what remains unresolved
The record assembled by GAO and summarized in congressional testimony shows substantial documentation of deployments and planning processes and persistent GAO recommendations to improve data, cost analyses, and comparative evaluations, but the sources do not contain a definitive, peer‑reviewed DHS or GAO study that quantifies, in a consistent way, the relative effectiveness of detection technologies versus physical barriers across all Southwest border conditions; therefore definitive statements about which approach is superior in every context cannot be drawn from the cited GAO and DHS assessments alone [2][1][3].