The TDOT project on Mem Fix Four (NSRR) required replacing a TDOT structure which spanned I-240 and carried one (1) mainline and one (1) siding track for NSRR. The structure was constructed using ABC techniques, measuring 342-feet, and weighed approximately 2 million pounds. TDOT was charged by NSRR to keep the railroad corridor operational and at speed during all phases of construction. TDOT was required to always keep one (1) track operational for trains to pass the construction site. NSRR operated the grade separated crossing at 45 mph during construction and experienced at least eight (8) trains per day. The maximum construction window was 12 hours on two separate days. The super structure was constructed on TDOT ROW. A temporary shoofly was constructed at the site to allow continual train movements which included the installation of approximately 1- mile of embankment, ballast, ties, and rails.

The substructure was installed underneath the existing operational structure and the offsite superstructure was hauled into location and lifted onto the bents and abutments during weekend closures of I-240. Due to the requirement of keeping the railroad operational and at speed and the need of a temporary shoofly, the superstructure was hauled in two sections during two different weekend closures. To move the superstructures into their permanent alignment, the superstructures were horizontally jacked into place.