Explosives detection for the United States' railway network needs to be improved, according to a government report released this week.

The Government Accountability Office (GAO) report, Explosives Detection Technologies to Protect Passenger Rail, says the threat of terrorist attacks using Improvised Explosive Devices (IEDs) against US railway infrastructure is a considerable one and that more needs to be done to evaluate new explosives detection technologies.

The report said: "To date, US passenger rail systems have not been attacked by terrorists. However, according to the Department of Homeland Security, terrorists' effective use of IEDs in rail attacks elsewhere in the world suggests that IEDs pose the greatest threat to US rail systems. Rail systems in the United States have also received heightened attention as several alleged terrorists' plots have been uncovered, including multiple plots against systems in the New York City area."

The GAO stressed they were not making any policy recommendations. It said their assessment was that new technologies "show promise in certain environments", but that further work was required to examine their potential effectiveness for the rail network.

Railway security

The GAO said current technologies including x-ray imaging, kit-based trace detection and handheld technologies "have demonstrated good detection capability", but that newer technologies present further opportunities to help improve railway security. Specifically these would include explosive trace portals, advanced imaging technology and standoff detection systems.

However, the GAO made it clear that "more operational experience would be required to determine their likely performance if deployed in passenger rail". The report also said there was greater co-operation required between government, industry and rail operators if the new technologies were to be harnessed effectively.

The GAO said the "shared responsibility for securing the passenger rail environment" between the federal agencies, rail operating companies and the security industry "could complicate decisions to fund and implement explosives detection technologies". The report said closer partnerships between these bodies was therefore increasingly important, both to assess the viability of technologies. The GAO also said it would be beneficial if a "concept of operations" were introduced that would help lay down guidelines and agreement "for using these technologies and responding to threats that they may identify", and to work out the financial, legal and privacy implications of using emerging technologies.