Decreasing traffic congestion has often been touted as the primary reason behind the use of ride-hailing apps. However, a new study, commissioned by ride-hailing giants Uber and Lyft, found that ride-hailing vehicles actually increases traffic congestion in major cities.

The study looked at combined vehicle miles traveled (VMT) in September 2018 in six major metropolitan areas: Los Angeles, San Francisco, Seattle, Chicago, Boston, and Washington, D.C. It revealed that ride-hailing vehicles' average VMT to be in the low single digits as a percentage when compared to overall vehicle traffic. 

In the Seattle area, Uber and Lyft rides made up 1.1% of VMT, the lowest percentage recorded in areas studies. At its highest in the San Francisco metro region, Uber and Lyft made up 2.7%. 

VMT numbers change when looking at metro region vs. core county.

For instance, while ride-hailing in the San Francisco metro area contributed 2.7% to total VMT, in core county, in made up nearly 13%. The gap is smaller in some areas, like Seattle, where VMT for the county increased to 1.9% on average.

Among the reports findings was the revelation that on average, Uber and Lyft drivers spend the majority of their time driving without passengers in the vehicle.