Mark Keller, P.E., a railroad engineer at Hanson Professional Services Inc.’s Chicago regional office, recently celebrated five years of service with the company. Keller, who joined the firm in 2015, designs bridge and retaining wall components for rail projects throughout the country. He received bachelor’s and master’s degrees in civil and environmental engineering in 2014 and 2015, respectively, from the University of Illinois at Urbana-Champaign, and is a licensed professional engineer in Illinois.