Of the large truss bridges over the lower Mississippi, the Interstate Highway I-10 Horace Wilkinson Bridge is the biggest of the big. It rises 175 feet above the water, making it the highest of any Mississippi River bridge, at least measured over the navigation channel (side spans of the Smith Avenue High Bridge in Saint Paul are taller, but its center span is 10 feet lower than the I-10 structure). The Wilkinson Bridge is 14,150 feet long overall, which is more than 2-1/2 miles. The truss superstructure is 4,550 feet long, and features a 1,235-foot clear channel span. The traffic deck carries six lanes of freeway traffic, seeing an average of 90,000 vehicles per day.
The I-10 bridge appears to drivers to have a very steep incline leading to the truss spans. I am often asked what the grade is, especially by over-the-road truck drivers. The incline is a bit of an optical illusion given that the area on both sides of the river is so flat and low. This makes the bridge visible from several miles. Once on the incline, vehicles make the climb quickly given the highway speeds. In reality, the incline climbs about 150 feet over the course of a mile, making for a grade that is around 2%.
Many local people refer to this bridge as the ‘New Bridge’, to distinguish the structure from the older US-190 bridge located 4 miles to the north. The bridge was officially named by the Louisiana state legislature in Act 206 in 1968. The act states, “These gentlemen served diligently, contributing greatly to the betterment of the state” when speaking of the three generations of Wilkinsons who served a total of 54 years in that body. There is some dispute if the state of Louisiana legislature had the authority to give an official name to a federally funded bridge. As a result, the official bridge name is not posted on Interstate I-10. The official name ‘Horace Wilkinson Bridge’ is not widely known. In fact, representatives have unwittingly introduced bills to the legislature on several occasions proposing to give the bridge an official name not realizing that the bridge had already been named.
While I visited on a somewhat gloomy day, the rain let up long enough for me to take photos both crossing the bridge, and from the west end of the bridge. With a bridge this large, it is nearly impossible to find a vantage point where you can capture a majority of the structure, yet not have obstacles in the way. Some of these photos were taken shortly after Hurricane Katrina, and I ended up getting chased out of the area two different times by FEMA security. FEMA apparently set up a base camp for New Orleans relief under the west end of the bridge. In a land where we are supposed to have government of the people and for the people, they sure are not very friendly towards the people.
The photo above is a view of the downriver face of the truss superstructure as seen from a vantage point southwest of the river crossing. The steel truss is such a massive structure that it dwarfs the deck truss approach spans, which are engineering marvels in their own right.
