“What’s also grown in that time is congestion in major cities. And while numerous factors obviously contribute to worsening traffic delays—population growth being number one, declines in transit ridership another—emerging research suggests that the mapping genie in your pocket may actually be one of them … when just 20 percent of drivers were using apps, the total time that all drivers spent in traffic actually increased.” CityLab: Killer Apps.

+ “The get-it-now age of Uber and Amazon has delivered something unexpected to Boston’s doorstep — new traffic that worsens our soul-crushing snarl.” A three-part series from the Boston Globe’s Spotlight team: Seeing Red.