The COVID-19 pandemic has been a disruptive force that has dramatically changed the US transportation industry. In four months, the precipitous decline in public transit ridership, air traffic, parking, toll road transactions, port container volumes, and overall mobility--up to 95% in some subsectors--has contributed to the current recession and the sharpest contraction in economic activity since World War II.

At S&P Global Market Intelligence, we ran different transportation scenarios to better understand the potential impact on the credit quality of each sector. Leveraging our "Public Finance Automated Scoring Tool or PFAST", there appear to be five key risk factors that are now driving transportation credit quality.