Tirzah Gregory has built a lot of bridges during her 25-year career with HNTB, one of the nation’s largest providers of bridge services. While most of her experience is with vehicular bridges, she has a special affinity for pedestrian structures.
Above: Tirzah Gregory, a 1994 graduate of Washington University's School of Engineering. Below: The Keepers of the Plains bridges that Gregory helped to design and build. Submitted photos
“There's something about pedestrian bridges that feels more intimate,” Gregory said. “You take your time going across them, so the experience is more fulfilling.”
Gregory started with HNTB right after graduating in 1994 with a bachelor’s degree in civil engineering from the School of Engineering & Applied Science at Washington University in St. Louis, and in 2016, she was named group director of the firm's bridge group. She’s the first woman to hold the position.
“At the Kansas City office, where I'm the group director, it’s even more of a special honor because that's where we started,” Gregory said. “HNTB is about 105 years old, and the original office is the bridge department in Kansas City."
In her role, Gregory manages a team of 68 engineers, an architect and technicians. She credits her natural strengths in people management and communication with helping her to thrive.
"I had to follow some big personalities in the role who were more technical, engineers of record on Mississippi River cable-stay bridges, but I didn't have to try to replace them,” she said. “I created a new way of performing the role and doing the job, and I think it's been pretty successful.”
Two of her favorite projects to lead were the Keeper of the Plains bridges in Wichita, Kansas, which cross the Arkansas and Little Arkansas rivers. The two cable-stayed bridges provide pedestrian access to a 44-foot steel sculpture donated to the city by Native-American artist Blackbear Bosin. The bridges were designed by an HNTB in-house bridge architect to resemble Native-American headdresses.
"I was really proud to have been a part of the team that designed that project,” she said. “I was able to take my children there to run over the bridge and experience their mom's design."
Gregory works to ensure that other women in the industry can have those same moments. As part of her advocacy for women in engineering, she serves as vice president of the Kansas City chapter of WTS International, a professional organization that promotes women in transportation, and recently began hosting regular meetings with female colleagues to foster networking and to discuss issues in the industry.
“The challenge of engineering comes down to solving problems,” Gregory said. “To be able to see a problem in its fullest and understand it well, you need different perspectives to provide their own view. Those different perspectives come from diversity of experience.”
Gregory says she’s optimistic about the direction the industry is heading. While structural challenges remain, more and more companies are realizing how vital a diverse workforce is.
"Companies are realizing that if they're going to lead and be at the top of their game, they're going to need women at the table,” Gregory said.