With the knowledge that natural disasters like earthquakes, hurricanes and wildfires can happen at any time, would your city be prepared to evacuate thousands, or even millions, of people?

A study conducted by forensic consulting service, Envista Forensics (formerly PT&C LWG), took a look at the 10 most populated urban metro areas in the United States and examined each city’s ability to evacuate successfully in the event of a disaster.

The study took into account a variety of factors, including roadway intensity (the number of lanes per thousand people), traffic congestion, the availability or ownership of automobiles, population density and geographical barriers like oceans, lakes and mountains.

Based on the study's findings, below are the 10 most difficult and easiest U.S. cities to evacuate, ranked from the five worst to the five best.

10 worst, best US cities for evacuation during a disaster

“Geographical barriers are often a pretty major factor,” said Dr. B.D. Wortham-Galvin, director of Clemson University's Master of Resilient Urban Design Program.

“Compare where I’m living in Charleston, South Carolina, which experiences hurricane threats during the season, to Washington, D.C., which has many directions in which people can leave the city,” Wortham-Galvin told AccuWeather.

The nation’s capital ranked as the fifth worst city to evacuate in the event of a disaster, according to the Envista Forensics study. This was based on low rankings in the areas of traffic congestion, internal traffic and roadway intensity.

However, on a scale of one (best) to 10 (worst), D.C. ranked highest in the areas of public transit and geographical barriers.

“Charleston is on a peninsula surrounded by a lot of water, which means that you are having a lot of people taking the exact same way out of the city, much like in Miami, compared to other cities that have multiple exits,” Wortham-Galvin said.

Miami also placed on the list as one of the most difficult U.S. cities for evacuations. The city, home to more than 2.7 million people in 2018, did poorest in the areas of exit capacity, traffic congestion and population density.

Infographic - Best and worst cities to evacuate

While five cities in total, including Chicago, New York and Los Angeles, ranked among the top worst cities to evacuate, five additional cities fared better on the list.

Texas is leading the way in terms of preparedness, according to the study, with Dallas and Houston taking the first and second spots on the list of easiest cities to evacuate.

The study found that Dallas did well in the areas of exit capacity, auto availability, geographical barriers and roadway intensity, while Houston excelled at having strong exit capacity and few traffic bottlenecks.

Communicating evacuation plans to the public

While many cities do have evacuation plans and actions in place – for example, switching traffic lanes to direct all traffic out of the area to a safer location – if the larger plan isn’t clearly communicated to the public during non-emergency situations, the plan will likely not be as effective as hoped, according to Wortham-Galvin.

Chicago, which was rated as one of the worst cities for evacuation, does have a plan in place, but the Chicago Emergency Operations Plan has not been made available to the public, according to the study.

"In the end, the members of the public are the ones evacuating,” Wortham-Galvin said. “If you’re really fully versed in your municipality’s evacuation plan in non-emergency moments, when an emergency happens rapidly, you have a better capacity as an individual to understand that plan and follow it.”

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She recommended that cities make frequent efforts to communicate their disaster plans to the public, including via social media, in multiple languages and at public meetings or major city events.

“It should be often and it should in be multiple ways, both digital and in person,” she said. “Also, they should never stop doing it, thinking, ‘We got the message out once, we don’t need to get the message out again.'”

While these types of studies are important, it's also essential to understand the implementation for the criteria of such studies, according to Wortham-Galvin.

"How is that criteria being implemented and how is it being communicated to the general public?," she said. "I think those things are going to be immensely important as we move forward as a country in understanding how to evacuate."

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