Why The Truck Speed Limit Is Lower

On the Lake Pontchartrain Causeway, maintenance is a key factor for keeping traffic moving, and the speed limits for both cars and trucks, especially at the bascule drawbridges, are important for not only the obvious reason. Heavily-loaded trucks going over the speed limit not only set up vibrations that can increase wear and tear on the bridge, but when they hit the ramps going up to the drawbridges, other forces come into play that can cause problems for the bridge alignments. 

 Here is an article I wrote in 1982 for the LMTA News magazine for truckers. Click on the image of the article to see a larger version.