2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/169296"Phantom jams," traffic blockages that arise without apparent cause, have long frustrated transportation scientists. Herein, we draw a novel homology between phantom jams and a related class of self-sustained transonic waves, namely detonations. Through this analogy, we describe the jam structure; favorable agreement with reported measurements from congested highways is observed. Complementary numerical simulations offer insights into the jams' development. Our results identify conditions likely to result in a dangerous concentration of vehicles and thereby lend guidance in traffic control and roadway design.6 pages, 4 figuresAnalysis of PDEsMathematical PhysicsPattern Formation and SolitonsPhysics and Society35Q80; 76H05; 90B20text