Tri-Level Interchange – New I-70 Over I-55 and I-642018-07-31T19:59:17+00:00

Project Description

Tri-Level Interchange – New I-70 Over I-55 and I-64

As part of the new bridge project over the Mississippi River at St. Louis, Interstates 55, 64, & 70 will now be split so that I-70 is diverted along a new alignment to pass over the new bridge and I-55 / I-64 will continue over the existing Poplar Street Bridge. TWM’s structural engineering staff prepared the curved girder erection plans for two of the structures on this project.These were 3-span structures ranging from 457’ to 487’ long with 7’ tall steel plate girders.TWM also designed temporary soil retention systems at several of the substructures and checked cantilever forming brackets.

Visit our Roadway Bridge page.

  • LOCATION: East St. Louis 


Exceptional Service. Nothing Less.


TWM continues the important business of supporting our nation’s essential infrastructure in these uncertain times. We are committed to our mission of providing Exceptional Service, Nothing Less to you, our clients and partners. As a professional services firm, the health of our employee-owners and their families is paramount. We are following government directives and public health guidance, implementing work-from-home and other social distancing and hand hygiene practices. We have employed additional technological resources to support our modified operating structure, and we expect to be able to do so with minimal disruption. If you need to visit our offices in person or have trouble reaching your TWM contact, please contact us at 618.624.4488 so we can make arrangements or put you in touch with the appropriate person. Thank you for placing your trust in TWM. Wishing you safety and good health.