We’ve all done it: Squeeze a balloon in one spot, and the contents migrate to a different part of the balloon. This analogy has been used in the context of Latin America to describe what happens in the drug trade when tighter security is applied to one area of production or trafficking, which results in the trade migrating elsewhere. Unfortunately, as recent events remind us, the same can be said for securing transportation infrastructure against terrorist attacks – but in at least one area of this problem, it may not have to be that way.
Since the September 11, 2001 terrorist attacks, it has become considerably harder for terrorists to get on planes in order to bring them down. Some of that undoubtedly has to do with good intelligence leading to apprehension of individuals before they arrive at the airport, and some of that is also attributable to the presence of airline security at key airports. Though the performance of the Transportation Security Administration (TSA) in the United States over the past decade certainly leaves a lot to be desired, and in some cases has been downright outrageous, one would be hard-pressed to argue that a TSA-type presence has had nothing to do with the lack of a repeat of a 9/11-style attack—even if there is room to debate whether TSA’s functions could be carried out more effectively by private industry.
Despite the fact that it’s become relatively harder to attack or hijack a passenger jet from the inside, terrorists have not lost interest in attacking mass transit systems – they’ve simply expanded operations to other less secure parts of those systems, such as the more publicly accessible sections of airports in places like Brussels last month or Moscow in 2011. Passenger trains and train stations have also been high-interest targets post-9/11, with detonations of explosiveson board trains in Madrid, London, Moscow, and, most recently, Brussels.
In the aftermath of the Brussels attacks, authorities in the United States and elsewhere are rightfully focusing attention on train security, increasing the presence of security officers on board trains in some areas, and inside high-profile stations. The danger, however, in focusing on the trains and the stations is the risk of paying insufficient attention to the third critical component of the rail system: the tracks themselves.
Tracks have been targeted, or at least have been identified as an intended target, in the past. In Pakistan earlier this month, two passengers were killed when, according to local authorities, an Improvised Explosive Device (IED) placed on the tracks was remotely detonated beneath a train en route to Quetta. Last year, five bombs were discovered on a single stretch of track in India before they could be detonated. Closer to home, a crude pipe bomb was found on the tracks by railway employees in northwest Indiana last year, in what was described as an isolated incident. Additionally, documents seized after the raid on Osama bin Laden’s compound indicate that Al Qaeda has previously taken an interest in attacking passenger trains by derailing them, particularly at bridges – one such plot in Canada was broken up by authorities in 2013.
These incidents may seem sporadic now, but it is entirely feasible that as trains become increasingly secure in the wake of Brussels, terrorist organizations will seek to conduct attacks in ways that do not require them to get past security personnel or navigate countermeasures.
To avoid the rail security version of the “balloon effect,” leaving a major component of the rail system vulnerable while squeezing others, policymakers need to incorporate securing the tracks into any strategy for protecting the system against attacks. Technology to monitor tracks to prevent derailments is in various stages of development, but the technology that appears to be furthest along at this point includes a sensor network that monitors tracks for deterioration to prevent stress-related derailments, not the placement of explosives.
There is also the Positive Train Control System, which has been around for several decades and can monitor train movements and, if necessary, control speeds at sharp turns. However, this system is designed to address derailments caused by excessive speeds and not by tampering or explosions on the tracks. Theoretically, it is possible to develop on-the-ground options for monitoring tracks for tampering or explosive devices, but such a system does not yet exist and would be extremely expensive to create.
There is one technology that could help security officials start to get a handle on this challenge: Drones.
Since last year, BNSF Railway, after receiving approval from the Federal Aviation Administration (FAA), has been experimenting with using drones to inspect thousands of miles of tracks across the country to spot defects on the tracks that could lead to derailments. The drone flights have the potential to increase the frequency and cost-effectiveness of track inspections by reducing the need to send human inspectors to look over, in person, every mile of track, including stretches in remote locations. On top of that, drones have already demonstrated their ability to locate IEDs on the battlefields of Afghanistan, protecting military personnel in the process, so spotting IEDs on railroad tracks is conceivably doable for these platforms.
While some technical challenges remain, drones appear to offer an option that is technically, and financially, more feasible than other technologies for the purpose of detecting possible security threats to the track portion of the rail system – assuming that the drones themselves can avoid becoming hazardous to other air traffic. The outcome of the BNSF/FAA pilot program should tell us more about what is possible in this area.
As Congress considers this year’s FAA reauthorization bill, policymakers would be well-advised to further explore ways in which drone technology could be further utilized to assist with rail security. Or we could watch as the risk of the next attack moves predictably to the vulnerable part of the balloon.
Ben Lerner is a Vice President with the Center for Security Policy. Grant A. Begley, who contributed to this article, previously served as Pentagon Senior Advisor for UAS/drones, in the Office of the Under Secretary of Defense.