Saturday, August 27, 2011

Evacuation Networks and Hurricane Irene -- When Selfish Travel is Actually Unselfish

For the past few weeks I have been busy working on my Transportation & Logistics lectures for the course that I am teaching this Fall at the Isenberg School at UMass Amherst.

In the course, students will be learning about different transportation (and network) behavioral and decision-making principles, including user-optimized (selfish) and system-optimized (unselfish) behavior, and the effects on travel times and costs, and I will also be covering aspects of disaster and emergency preparedness and other timely topics.

Now, we are awaiting Hurricane Irene, and western Massachusetts is forecasted to be in the eye of this hurricane tomorrow afternoon, Sunday, August 28. Governor Deval Patrick has declared a state of emergency as have many other governors of states along the Northeast Corridor of the Unites States where 1 out 5 Americans live.

For the first time in history, NYC, with a population of 8 million, has issued an evacuation order to those living in low-lying areas, which is affecting over 370,000 people, with certain hospitals and nursing homes already evacuated.

Evacuations have also been issued in parts of North Carolina and New Jersey and I was impressed that the Providence Journal (I went to Brown University and we have relatives in Rhode Island) even posted evacuation maps for different localities in Rhode Island!

Maps are, of course, extremely useful as are GPS systems, but neither provides the true picture of what happens when thousands of vehicles flood the roads in the case of an emergency and evacuation since they do not capture congestion. Hence, the roads may be jam-packed as travelers seek to reach points of higher ground inland and safety. Moreover, if everyone uses the "shortest" recommended route, which does not include the travel time due to congestion (the number of vehicles on that road) it may actually become the "longest" one -- dangerous when a hurricane is approaching.

Hence, what should be done, for equity and fairness, interestingly enough (and I have been doing a lot of thinking and research on this topic) is to have the traffic be routed in an evacuation in a user-optimized manner so that all routes have travel times, from each origin to safe destination, that are equal and minimal. This is actually how commuters behave in selecting their cost-minimizing routes of travel and, in an emergency, user-optimization or selfish behavior actually is unselfish!

With the mass transit shutdown in NYC as of noon today, there may be large traffic jams but I am impressed by the attention that has been given to making sure that the subway and train cars are protected. Even tolls (which I also teach about in my course) will be eliminated to assist in the timeliness of evacuations and the flow travel time.

We have stocked up on bottled water, nonperishable food, batteries, and have our flashlights and radios ready as well as our cars filled with gas.

Regions in the Northeast may be without power for as long as a week so one has to be prepared.

We are expecting pounding rain for 10 hours or so with winds up to 70 miles an hour in our area, beginning tomorrow. By that time, only emergency vehicles should be on the roads.

In fact, even our campus is officially closed for 48 hours this weekend.

For more background on our critical infrastructure systems and their resiliency (or not), please see the article, "Fragile Networks: Identifying Vulnerabilities and Synergies in an Uncertain Age," co-authored with Dr. Patrick Qiang, who's recent statement on disasters and rare events, including our recent earthquake and now Hurricane Irene, appears on his university's website.