What Pishue did for us was use the INRIX travel time data on four stretches of highway around D.C. for Dec. 23, 24 and 25 in 2013, 2014 and 2015. The highways are four of the main escape routes: I-95 in Maryland, I-95 in Virginia, I-270 and I-66. The Dec. 23 information is helpful, because we’ve learned from INRIX and other sources in recent years to worry about the eve of the eve of a holiday, when getaway drivers mingle with regular commuters.
In general, Pishue said of the historical data, “travel times on Christmas Eve and Christmas Day are close to those seen at night — meaning free-flow — yet travelers on Friday [the eve of the eve this year] may experience increased levels of congestion on certain stretches of highways.
“A closer look at I-95, for example, shows Dec. 23 travel at 5 p.m. in 2013, 2014 and 2015 are higher than the average for that weekday in December, suggesting that drivers on Friday, the day before Christmas Eve, may experience an increase in travel times. However, with Christmas on a weekend, many employees and employers may opt for a four-day weekend, reducing travel demand on the region’s highways.”
The charts below will display Pishue’s INRIX data for the four routes. In reviewing them, note that in 2015, Christmas Day was a Friday; in 2014, it was a Thursday; and in 2013, it was a Wednesday. One thing I see consistently is that an early morning getaway has worked a lot better than late afternoon escapes.
The first chart shows traffic southbound on I-95 between the Capital Beltway and the Fredericksburg area in Northern Virginia.
Next is the northbound version for I-95 in Northern Virginia.
The charts below show the Maryland side of I-95. First is the northbound traffic, followed by the southbound.
Coming up is the historical travel time data for westbound I-66.
The final image shows travel times for drivers heading away from the Capital Beltway on I-270.
Note that all of the INRIX charts show average travel times for the entire segments. One thing I’ve noticed in looking at traffic maps and cameras in real time during holiday getaway periods is that the traffic flow along a segment is inconsistent. From one exit to another, you may get a chance to speed up, then be disappointed with another stretch of slow-moving traffic.