Uber and Lyft are behind a sharp rise in US traffic deaths

The rise of ride-sharing services has increased traffic deaths by 2% to 3% in the US since 2011, equivalent to as many as 1,100 mortalities a year, according to a new study from the University of Chicago and Rice University.

How it was calculated: Researchers took statistics from the National Highway Traffic Safety Administration and compared them with the dates Uber or Lyft launched in a specific city. Then they checked accident rates in those cities relative to vehicle miles traveled. That rate shot up in San Francisco after Uber launched in 2010, a phenomenon that was replicated in other cities.

Deadheading: The increase in congestion is partly because drivers spend 40% to 60% of their time searching for passengers, a practice known as “deadheading.” On average, drivers in New York City traveled 2.8 miles between fares.