After an Islamic State sympathizer rammed a truck into crowds celebrating Bastille Day in 2016, horrified New Orleans leaders were eager to protect their city's famed French Quarter, where crowds of revelers pack the cobblestone streets, especially during big events like Mardi Gras.
By the next year, steel columns known as bollards were installed to restrict vehicle access to Bourbon Street. The posts retracted to allow for deliveries to its bars and restaurants, until — gummed up by Mardi Gras beads, beer and other detritus — their tracks stopped working reliably.
