<i>São Paulo's speed limits are automatically enforced by traffic cameras, so drivers are highly incentivized to comply. "If you’re driving in São Paulo and you go above the speed limit, you’re sure you’re going to get a ticket," Vieira says. "I was surprised when I was [in America] that you don’t have automatic enforcement."</i><p>The only reason US municipalities are willing to install auto enforcement is to fatten budgets. It's a perverse incentive and it band-aids the core fault of having cars in places that ought to be pedestrian spaces.