Private-public resilience profile: I-95

On Sunday, June 11 the driver of a gasoline tanker truck lost control on the Cottman Avenue exit from Interstate-95 in Philadelphia. The resulting fire caused the elevated deck of the northbound Interstate to collapse and seriously damaged the southbound deck. The driver did not survive. Since the accident, several miles of Interstate-95 have been closed to traffic.

City and state officials took quick action to divert traffic, extinguish the fire, establish detours, expand public transit options, and facilitate freight flows on other routes. Up to 160,000 vehicles per day often travel the disrupted route (AADT and more and more).  This includes up to 20,000 freight-hauling trucks per day.  On most days three-quarters of this freight volume is focused on serving the immediate urban matrix in Southeast Pennsylvania. 

Local carriers have — with difficulty — adapted to the impediment. Most long-distance flows actively avoided this densely traveled route even before the incident. 

On the best days, Interstate travel in the Philadelphia region can often be congested. Closure of this segment of I-95 has increased congestion and slowed both commuter and freight flows. Freight flows discharging into and out of central Philadelphia have been especially impacted.  While longer distance flows have been less impacted, the additional friction has time and cost implications that are acute for some carriers and consumers and have been accumulating across the region.

Federal, state, and local leaders all promised quick action to restore the lost network segment. Less than two weeks later, a temporary solution just reopened to flow. According to the Associated Press, “… Workers [have filled] the gap — which is roughly 100 feet (30 meters) long and 150 feet wide — by piling recycled foam glass aggregate into the underpass area, bringing it up to surface level and then paving it over so that three lanes of traffic can reopen each way…”

The glass aggregate is produced by AeroAggregates of North America. The company operates south of Philadelphia where it processes recycled glass bottles and jars into powder that is then heated into a foam to produce small, lightweight glass nuggets. The company’s CEO, “estimated that it will take about 100 box-truck loads to haul about 10,000 cubic yards (7,600 cubic meters) of the glass nuggets required for the I-95 project. The total weight is around 2,000 tons, a fraction of the weight of regular sand or dirt, meaning that it will take many fewer trucks to bring it to the site…” More on this innovative solution is available via the week-old local TV news report below.

This morning — Friday, June 23 — two fire-trucks were the first two vehicles to cross the reopened section (more and more).

Resilience implications: The importance of this channel — this concentrated capacity — was widely recognized by both private and public sectors. Coordinated intergovernmental funding and action was taken to expedite mitigation. Private sector flows adapted as possible. Public sector decision-makers sought out innovative means of reopening the channel. Upstream has now reclaimed its downstream capacity in less than two weeks. It does not always happen this way. It is absolutely worth celebrating when it does.


June 28 Update: Very nice after-action from Bloomberg. Here’s a taste: “The fast feat was “a small miracle” in many respects. What made it possible: emergency, no-bid contracts, around-the-clock repair crews, a guarantee from the federal government to pick up the check, and no small amount of Rust Belt ingenuity.”

September 3 Update: In late August the Washington Post ran a related story headlined: “Avoiding ‘carmageddon’ after the I-95 collapse“. Some details confirming what is outlined above.