ASDE-X ground surveillance covers only 35 of America's 500+ towered airports, leaving the vast majority without automated runway incursion detection technology

The FAA's ASDE-X (Airport Surface Detection Equipment, Model X) system -- which uses radar, multilateration, and ADS-B to track aircraft and vehicles on runways and taxiways and alert controllers to potential conflicts -- is installed at only 35 of the busiest US airports. The remaining 470+ towered airports rely entirely on controller visual observation, which is degraded at night, in fog, and during precipitation. In 2024, the FAA recorded 1,664 total runway incursions across US airports. Why it matters: At airports without ASDE-X, controllers must visually scan the airport surface to maintain awareness of all aircraft and vehicle positions, so at night or in low-visibility conditions their ability to detect unauthorized runway entries drops dramatically, so runway incursions at non-ASDE-X airports go undetected until they become near-collisions or worse, so the FAA's recent $100M+ investment in runway safety technology only benefits the 35 airports that already have the best safety infrastructure, so the risk-per-operation is actually highest at medium-sized airports (like Dekalb-Peachtree with 103 incursions in 2024) that have significant traffic volume but no automated surface surveillance. The structural root cause is that ASDE-X installation costs $15-25 million per airport and requires significant infrastructure (radar towers, multilateration sensors, fiber optic networks), making it economically infeasible for all but the highest-traffic airports under the FAA's current Airport Improvement Program funding model -- even though runway incursion rates at mid-tier airports are often higher per operation than at the large hubs that have the technology.