Surface Transport Terror Threats: ‘Soft’ Targets, Hard Security Challenge

November 8, 2021

By Deepti Govind

We set the stage in a piece published about two weeks ago, on examining the kind of threats surface transportation around the world has faced from terror actors over time. To quickly recap what we said then: While the number of attacks on large surface transportation modes, like railways, remains statistically low in economically advanced countries, globally the number of attacks with 25 or more fatalities has been growing. What possibly makes surface transport — whether buses, trains, passenger ferries, etc. — attractive targets is that it gives terror actors access to crowds, and it is also relatively easier to carry out attacks on these modes of transport without using sophisticated weapons or strategies.

In this piece, the second in our mini-series on terror threats to surface transportation, we examine the kind of methods terror actors have used to attack these modes of transport. We also take a look at what authorities have been doing to combat this threat.

Soft Targets, Primitive Methods

There’s no single definition, but there are certain attributes that could make experts label a terror attack “sophisticated,” according to a paper published by the Mineta Transportation Institute (MTI) and San Jose State University in June 2020. For instance, the paper says, a terror attack may be considered sophisticated if:

• It involves multiple operatives with different assigned roles
• Adversaries may be able to recruit someone who can provide them with “inside assistance,” i.e., an insider threat, or are able to gain access to information about a target that is not easily available to the public
• Requires specialized skills or training; for example learning how to fly commercial jets in case of attacks on the aviation industry
• Envisions closely coordinated operations against multiple targets
• Involves the penetration of manned or closely monitored security perimeters or overcome significant physical barriers

The 9/11 attacks are considered to be sophisticated even though the kind of weapons used were rather primitive in nature (box cutters, utility knives, and pepper spray). Why? According to the same paper:

• To begin with, the operation itself took years to plan. It involved the Al Qaeda drawing on its global resources to recruit for and finance the attack and for operational support
• The 19 hijackers were selected after a stringent vetting process. Six of them enrolled in U.S. flight schools to learn how to fly large commercial jets. The others provided the “muscle” for the operation
• Many of the attackers were instructed to obtain new passports, some of which were altered by Al Qaeda document specialists to facilitate entry into the U.S. All were instructed to obtain U.S. driver’s licenses so that they would not have to use their Middle Eastern passports and risk attracting attention
• The attackers also spent months watching security procedures at airports, taking reconnaissance flights, and making test runs with the weapons they thought they could pass through security

But the 9/11 attacks fall under the relatively less common category of sophisticated terror acts. As we mentioned in our previous piece on the subject too, given primitive attacks logically lead to less damage, can we afford to be lax about security? Definitely not. Terror actors can attack anything, anywhere, anytime, using any weapon — from the most rudimentary to the complex (like the Tokyo subway sarin gas attack of 1995).

On the other hand, when it comes to surface transport terror attacks, none of them (until 2019) involved penetrating any formidable security measures, according to the MTI-San Jose paper. Six attacks involved devices or techniques that could be considered sophisticated, while five involved coordinated multipart attacks that could be considered complex, the paper added. For example, using public stabbings as a terror tactic is a recent phenomenon, although it has been the method most associated with homicides.

Per a 2019 MTI report, trends also point to a long-term increase in terrorist vehicle ramming attacks, but that increase “also appears to reflect a contagion effect in which one attack inspires another.” Stabbings and vehicle ramming are both considered primitive in nature according to the MTI-San Jose paper. “The weapons—a knife, a vehicle—are readily accessible, and although some of the attacks are well-planned, planning is not necessary. Some of the attacks appear to be spontaneous,” the paper adds.

Securing Surface Transportation

The Department of Homeland Security (DHS) has also labeled surface transport a “soft target.” Unlike aviation, where you have established security checkpoints at the airport, the sheer volume of passengers and the open environments they operate in makes a fixed security checkpoint tougher to implement when it comes to surface transportation. Then there is the massive challenge of adequate resources and manpower to protect every stretch of surface transportation.

Like we mentioned in our earlier piece, Al Qaeda’s “Inspire” magazine itself spells out why the rail industry makes for an “attractive” target, according to an article in Homeland Security Today from March 2019. The article says it’s practically impossible for America to protect its “240,000 km of railroad.” At the same time, given the volume of passengers who use these modes of transport on a daily basis, they offer terror actors the “opportunity” to cause a lot of damage if their plots succeed.

In a 2017 post, the DHS said the Washington Metropolitan Area Transit Authority (WMATA) is one of the busiest transit systems in the nation, averaging about 712,000 trips per weekday. Metro Transit Police are acutely aware that rail and subway systems are susceptible to attacks or other acts of violence, due to both the high volume of commuters and the open, unstructured nature of the environment, it added.

And, as we said earlier, fixed security checkpoints come with too many practical challenges to be viable. Therefore, identifying potential threats on people and in their bags without physically interacting with them or impacting their movement through the system is challenging. One solution that the DHS lists out could be if there was a way to detect potential threats in bags or on persons from the moment they entered the subway. And if there was a way to know the path individuals take as they move through the system, and to relay that information to transit police in real-time. That’s where the Department of Homeland Security (DHS) Science and Technology Directorate (S&T) comes in.

S&T’s Surface Transportation Explosives Threat Detection (STETD) Program, per the DHS’ 2017 post, is testing a potential solution to this challenge and aims to provide the surface transportation end-user community with the capability to screen for potential threat items at the speed of the traveling public. “Basically, we are taking a ‘Curb to Platform’ approach to security,” Don Roberts, S&T Program Manager said. The “Curb to Platform” approach uses a network of different sensors distributed at various points throughout rail and subway systems. It will allow authorities to get multiple perspectives for better detection without alerting the subject.

“One such STETD Program technology is the Intelligent Video algorithm designed by Johns Hopkins University Applied Physics Laboratory. The algorithm can detect a leave-behind item while reducing the number of false alerts transit police must resolve on a daily basis. Another technology, the Forensic Video Exploitation and Analysis (FOVEA) tool developed by MIT Lincoln Laboratory, enables security personnel to tag a person to a left-behind item and then reconstruct the path of that individual across multiple camera views. With FOVEA, hours of video can be scanned much faster than it would normally take, making the process more efficient and more effective. These tools are being tested now by WMATA and Amtrak,” the DHS said in its 2017 post.

These tools are being developed with the hope that they’ll solve some of the biggest challenges of securing surface transportation from terror actors, while keeping the personal privacy of passengers intact, without disruptions to the flow of passengers, and on the principle that it’s “impossible for law enforcement officials to be everywhere all the time.”