Dark intersections can take an outsized toll on both drivers and services. Last year's Hurricane Irma exemplified the costs: with more than half the traffic lights in Miami-Dade County out, road crews scrambled to deploy limited numbers of generators; police and sheriffs departments were stretched thin trying to direct traffic manually and writing tickets to drivers mishandling the outages; and accidents were caused by confused drivers blowing through dark intersections. While a hurricane like Irma doesn't happen every day, any dark intersection is an accident waiting to happen, and two-thirds of those are injury accidents, according to a New York DOT study. For the sake of drivers, DOTs, and first responders, transportation departments need strategies to minimize the occurrence and duration of traffic signal outages.
Knowledge is power, and the city of Portland, Oregon, is about to use the power of knowledge to save lives. As part of its Vision Zero Program, the city is deploying a network of smart sensors along its three most dangerous streets to gather data about the speed and flow of traffic. Traffic system designers will analyze data from the sensors to figure out what's not working and how to make those and other city streets safer for motorists, bicyclists, and pedestrians.