TPB News

Analysis Quantifies Drop in Roadway Congestion During Recent Papal Visit

Oct 21, 2015

A Transportation Planning Board analysis has quantified the traffic effects of Pope Francis' recent visit to the Washington region. The analysis, which showed sharp drops in rush-hour congestion on area roadways during the visit, demonstrates that modest reductions in driving during peak periods can yield dramatic improvements in travel conditions.

To quantify the exact effects of the recent visit, TPB researchers compared average travel speeds on area roadways during the week of September 21-25 to the preceding week. The analysis used commercially available speed information provided anonymously by drivers and other travelers via their GPS-equipped smartphones and navigation devices.

The analysis showed that congestion declined significantly on Wednesday and Thursday, September 23 and 24, the days of the Pope's public events in Washington. On those days, the inbound drive on Virginia's I-395 between the Beltway and the Potomac River took just 12 minutes during the height of the morning rush, compared to 44 minutes the week before. On I-270 in Maryland, the drive from the ICC to the Beltway dropped from 38 minutes to 11 minutes.

Key Travel Impacts During Recent Visit by Pope Francis

But the analysis found that these major reductions in congestion resulted from fairly modest reductions in overall travel demand. During the period, freeway volumes declined 4% compared to the same time one week earlier, while congestion decreased 10% and travel time reliability improved more than 30%. Between 8:00 and 9:00 a.m. on those days, the study found an even greater disproportionate impact: a 2% reduction in freeway volume and a 27% decline in congestion.

More: Read the full analysis of travel impacts during the recent Papal visit

The Pope's visit affected transit ridership, too. Compared with the previous week, ridership on the region's transit systems declined 7% during the week of the Pope's visit and an average of 17% on September 23 and 24. Ahead of the events, planners had anticipated higher-than-normal ridership due to out-of-town visitors crowding onto already packed trains and buses. But the increase in visitors was offset by a much larger decrease in system use by regular commuters who stayed home to avoid the predicted crowds.

Staying home seems to have worked. Increased teleworking has been cited as the major reason for the reduction in travel demand. The U.S. Office of Personnel Management asked federal agencies to allow employees to telework, adjust their work hours, or take time off during Pope Francis' visit. Many other employers also implemented similar telework and flexible work-hour policies.

The significant reduction of freeway and region-wide congestion during peak hours could be an indication of the contributions from workers that took advantage of telework and flexible work hours arrangement policies, and could encourage further use of such programs. Planners caution, however, that teleworking and flexible work hours are probably not a silver bullet for congestion. They note that the Papal visit was a highly publicized event occurring during a very limited time period, and telework and flexible work hour-derived congestion relief of the magnitude recently experienced was a result of an extraordinary event.

Past TPB analyses using the speed data from GPS-equipped smartphones and navigation devices have examined the traffic impacts of an observed decline in driving following the national economic recession, the before-and-after effects of the new Intercounty Connector in Maryland, and changes in driving patterns during summer months when schools are out and Congress is in recess.

Each quarter, the TPB publishes a report summarizing the latest hour-by-hour trends in congestion on area roadways and highlighting the effects of any special traffic events that occurred during the study period. The quarterly reports, each of which has a unique story to tell about regional travel patterns, are available at The page also features a regularly updated "Congestion Dashboard."

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