bridge even though Modjeski himself died in 1940. Though truss bridges increasingly fell out of fashion after World War II, this bridge's truss design, especially its main span, was largely dictated by the neighboring Frisco & Harahan Bridges and the established navigation channel beneath them. Construction on the bridge began on September 12, 1945, and the bridge opened to traffic on December 17, 1949. Later history Though Crump Boulevard was originally intended to serve as the main access to the bridge from Memphis, TDOT replaced the west end of Crump Boulevard with a stretch of I-55 in the 1960's. The issues resulting from the cloverleaf interchange at I-55 and Crump, required to accommodate a 90-degree change in I-55's direction onto the bridge, have led to more recent traffic problems including a failed TDOT plan that would have required a long-term closure of I-55 and the bridge in order to reconstruct the interchange, as well as lane closures and other issues at the interchange during the 2021 I-40 bridge closure during which this was the only open bridge at Memphis. On August 12, 2012, a cyclist was killed after being struck by a vehicle when using the shoulder approaching the bridge. On December 23, 2014, numerous news sources reported that the FBI had released an official statement warning local law enforcements of a threat to the bridge during that month. The FBI stated, "according to an anonymous complainant... ISIS instructed an ISIS member, a presumed USPER (U.S. person) in Memphis, with a direct order to blow up the Memphis–Arkansas bridge on an unknown date, activating ISIS terror cells in the United States." Security was heightened, but the threat was later discredited. Traffic mix Annual average daily traffic (AADT) figures reported by the Tennessee Department of Transportation for 2018, three years before the notable 2021 closure of the I-40 Hernando de Soto Bridge or "new bridge", show that the I-55 "old bridge" carries substantially more vehicles (64,520) than the I-40 bridge (37,308) despite its being older and narrower. Meanwhile, similar figures reported by the Arkansas Department of Transportation for 2020, the year before the I-40 bridge closure, from devices that also measure percentage of truck traffic suggest that though the I-40 bridge had slightly more vehicles (47,000) than the I-55 bridge (45,000), the I-55 bridge actually had a higher percentage of truck traffic (37 percent) than the I-40 bridge (26 percent). These