Treyger is a nationally recognized bridge structure design expert specializing in complex foundations in seismic conditions. He has designed a wide range of bridges, including suspension and cable-stayed structures, steel and concrete arches, and concrete segmental bridges and tunnels, several of which have been recognized with national awards for their excellence in design. He is one of HNTB’s foremost experts in the seismic design and retrofit of structures, providing both design services and quality control review for HNTB projects throughout the United States and abroad.