In partnership with advisory board member Amy O’Leary, Ph.D., Associate Director for Environment, Planning and Economics Research at the Virginia Transportation Research Center (VTRC), VA’s LTAP is pleased to present a series of on-going research spotlights. Every few months, we’ll bring you updates about research being put into action to increase efficiencies and provide sustainable transportation solutions.



This month’s Research in Action features a study conducted by a team of University of Virginia and VTRC researchers to tackle traffic congestion associated with the July 4th Independence Day holiday. For many years, the Virginia Department of Transportation (VDOT) has provided the traveling public with maps ( showing varying amounts of highway traffic by time of day, based on historical traffic congestion data, for Memorial Day, Labor Day and Thanksgiving. These are holidays falling on a fixed day of the week every year, providing travelers with a recognizable, established long weekend. Accounting for unexpected weather, fuel prices, the economy and crashes, traffic behaviors generally remain consistent.

For fixed date holidays such as Christmas, New Year’s Day and Independence Day, the role of the day of the week on which the holiday falls has to be examined. For example, travelers may make different travel plans if a holiday falls on a Tuesday, Wednesday or Thursday rather than a Friday, Monday or weekend. The research team of Michael Fontaine, PE, PhD, Associate Principal Research Scientist at VTRC and a Lecturer in the Department of Civil and Environmental Engineering at the University of Virginia, Simona Babiceanu, Transportation Systems Engineer in the Department of Civil and Environmental Engineering at the University of Virginia and Shraddha Praharaj, PhD Candidate in the Department of Civil and Environmental Engineering at the University of Virginia, set out to develop a methodology to establish day of week travel characteristics for the Fourth of July holiday period.

Hampton roads microscopic site for July 4th holiday travel study

The team collected historical data, covering the entire Virginia interstate system, to identify general July 4th travel trends. In addition, they studied a specific highly-traveled holiday corridor, encompassing I-64 South of Williamsburg and traversing Newport News and Norfolk as well as I-264 connecting Norfolk and Virginia Beach, to infer detailed localized holiday travel trends. The study period consisted of seven days from the 1st to the 7th of July, 2011 to 2016 for the entire 24 hours of the day.

Statistical analysis and modeling revealed some consistent travel patterns:

  • July 4th traffic is less congested everywhere and similar to July 4th traffic from other years, irrespective of day of week.
  • Sparsely populated and pass-through zones or relatively uncongested urban areas are not impacted by the Fourth of July holiday and do not suffer a day of week or day of month variation due to the holiday.
  • In congested urban areas, which are also gateways to popular summer attractions, the addition of the holiday tourist traffic is not enough to compensate for the drop in regular commuter traffic caused by the holiday, resulting in improvements in congestion on the Fourth of July.
  • Most of the congestion in tourist areas is short lived and related to special events specific to the holiday (in this case fireworks), and dissipates over short distances.
  • In congested urban areas, traffic seems to ease during the holiday travel period. This effect is more pronounced if the holiday is on or next to a weekend, with extended positive impacts to the day just before and after the weekend. For example, if the Fourth falls on a Monday, congestion is relieved in the period from Saturday to Monday.

Looking for some specific travel advice for travelling Virginia’s highways on July 4th?

Good news for travelers planning a day trip to participate in the July 4th celebrations in the nation’s capital: congestion relief is felt in Northern Virginia on the entire day and also on 5th.

For those thinking of going to the Beach: afternoon traffic is better than expected, as travelers are not encountering commuter traffic. Morning traffic is not eased as much, but that should be less of a problem for vacationers.

For travelers in Richmond and more rural areas, it appears July 4th travel is generally unaffected, regardless of the day on which the holiday falls.

These results validate the use of historical data to predict holiday traffic patterns. In addition to providing pre-trip planning information, these predictions can assist commercial operations, such as trucking and car rental companies, and hospitality, retail and tourism industries, to manage the effects of peak holiday travel times on their businesses. Regular commuters working on established holidays may also benefit from advance knowledge about holiday travel patterns, adjusting their work schedules to commute during less congested periods.

“Although apps such as Waze offer real-time information for making quick travel decisions on-the-go, travel info services offered by transportation agencies provide timely information for making informed decisions about travel times and routes prior to departure,” explained Babiceanu. “Creating useful information from historical data reveals the real power of statistical analysis.”

The next challenge will be to study travel patterns during the holiday season around Christmas and New Year’s Day. In addition to the different day of the week travel pattern, this analysis is more challenging since the travel period often spans more than a week.

For more information, contact Simona Babiceanu at

About VTRC

The Virginia Transportation Research Council (VTRC) is one of the country’s leading transportation research centers. Specializing in applied research to support VDOT, its scientists and engineers also provide technical consulting and training to promote innovations in structures, pavements, materials, safety, operations, traffic engineering, planning, environmental, and economic issues.

The goal of VTRC is to conduct research that enables VDOT to deliver transportation initiatives that save lives, save time and save money, while protecting Virginia’s environment.



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