A buried composite arch bridge system using concrete-filled fiber-reinforced polymer tube arches was recently developed for short span bridges. The research reported in this and a subsequent paper seeks to advance understanding of soil–structure interaction in these bridges through laboratory testing and numerical modeling simulations of subscale arch systems. This paper focuses on the experimental testing of stiffness-matched, half-scale three-arch bridge systems with 5:1 and 8:3 span-to-rise ratios tested in a controlled laboratory environment. Arches were cast in concrete foundations, placed in a self-reacting, timber soil box, and covered with decking. Deflection, strain, and soil pressure were recorded at eighth points along the span of the center arch and only at the apex and foundations of the outer arches. The bridges were backfilled with lifts of compacted granular soil until soil grade elevation was 610 mm above the decking apex. The bridges were loaded with a sequence of line loads at seven different positions along the span and were then loaded to failure with an apex line load. Experimental results reported here include the effects of backfilling, service live-load testing, and ultimate loading.