Do transportation network companies decrease or increase congestion?

Out-of-service travel is estimated at about 50% of TNC vehicle miles traveled (VMT) in New York (2) and 20% in San Francisco (1). We further processed the data to associate TNC volumes, pickups, and drop-offs to each road segment in San Francisco by time of day (TOD). To control for other factors that may also affect congestion over this period, we used San Francisco’s travel demand model, SF-CHAMP, which produces estimates of traffic volumes on all roads in San Francisco and is sensitive to changes in population and demographics, employment, transportation networks, and congestion.

Source: advances.sciencemag.org