COVID-ERA CONGESTION TRACKER

 

COVID-Era Congestion Tracker

Explore how congestion in San Francisco has changed since the March 2020 shelter-in-place order. Automobile Level-of-Service (LOS) and Vehicle Miles Traveled (VMT) per mile are presented for key segments in the transportation network. In addition, changes in these metrics relative to pre-COVID conditions can be viewed.
The LOS are calculated using speed data from INRIX Roadway Analytics. Speeds are monthly averages calculated using data from Tuesday through Thursday of each week. VMT estimates are derived using imputed vehicle volumes from observed speeds and Volume Delay Functions (VDF). Total peak period VMT for key segments is expanded to Daily Citywide estimate by applying expansions factors derived from historic Caltrans VMT estimated for San Francisco. The data on this website are updated every month.
  • Auto Level-of-Service (LOS) grades road segments by vehicle delay with "A" describing free flow, and "F" describing bumper-to-bumper conditions.
  • Speed Change Relative to Pre-COVID shows the percent difference between average speed of a segment and the speed under pre-COVID conditions (from the week of 3rd March 2020). Lower and negative values imply that speeds have droppped back to pre-COVID levels.
  • Vehicle Miles Traveled (VMT) is normalized by the length of the segment and could be interpreted as approximate average daily traffic volume.
  • VMT Change Relative to Pre-COVID shows the percent difference between daily VMT estimate of a segment and the VMT under pre-COVID conditions (from the week of 3rd March 2020). Higher and positive values imply that VMT have risen back to pre-COVID levels.

How to use this map

  • Move the month slider to update map with data from chosen month. Click the play button to automatically cycle through months.
  • Choose time period to update map for AM (7a-9a) peak, PM (4:30p-6:30p) peak or 1-Hour time periods.
  • Choosing the 1-Hour period provides an additional time-of-day option to update the map for a given hour of the day.
  • The chart on the side panel shows trends across the months when AM or PM peak periods are selected. It shows the variation across an average day when 1-Hour time period is chosen.
  • Click on a roadway segment on the map to see segment-specific trends.