SAN FRANCISCO, CA — The San Francisco County Transportation Authority released a report on Tuesday linking a rise in traffic congestion in the city to ride-hailing services like Uber and Lyft.

According to the report, “TNCs & Congestion”, the companies’ vehicles account for about 50 percent of the rise in congestion between 2010 and 2016.

The report took into account three factors, including vehicle hours of delay, vehicle miles traveled and average speeds.

“Understanding the factors of congestion is key to our ability to address the problem effectively and maintain the accessibility of our downtown core. We are committed to data-driven analyses like this report to serve as the foundation for deeper understanding and informed action,” SFCTA executive director Tilly Chang said in a statement.

According to the report, other factors responsible for worsening congestion include employment opportunities and population growth. The report also indicated that ride-hailing services caused
increased congestion at all times of the day, but they had the greatest impact on evening congestion.

Additionally, ride-hailing services had the greatest affect on congestion in the densest parts of the city, accounting for up to 73 percent of the increase in the city’s downtown area.

“This report further quantifies the impact ride-hail services have on our streets,” Supervisor Aaron Peskin, who also serves as the chair of the SFCTA Board, said in a statement. “It underscores the importance of our current collaboration with Transportation Network Companies to develop a per-trip tax to help mitigate the impacts of these trips, and informs our efforts to balance the availability of these new mobility options with our Transit First policies.”