The climate of this region over the river has been bad for steel. Galvanizing was selected for it's durability to withstand the elements, including sand and wind.
This region of the world needs bridges, and the fact that this was accomplished has opened a new market for American bridge galvanizers.
The galvanizer had to galvanize the steel, palletize the material, stack and package containers, and meet barge shipping times. They also had to come up with a way to eliminate the possibility of wet storage or white rust. This was accomplished by the use of hot-dip galvanized steel, and will be enjoyed by motorists in Tanzania for many, many decades.