The bombings in Madrid exposed the vulnerability of train networks around the world. Barbara Benham reports on what's being done to make them safer

On April 5, Queen Elizabeth hopped aboard the Eurostar, the high-speed train that connects Britain and France via the Channel Tunnel, en route to Paris. The occasion was the centennial of the Entente Cordiale, a dusty bilateral accord aimed at settling colonial rivalries between the two countries. But given recent events—from the commuter train bombings in Madrid on March 11 to the discovery, in three separate incidents, of bombs on tracks in both Spain and France—the subtext was clearly rail security: If trains are safe enough for the queen, they're safe enough for the general public, right?

Statistically, trains remain the safest form of transportation after airplanes. Following the Madrid bombings, however, their safety was called into question. Government and rail officials around the globe have responded by stepping up rail security in a variety of ways, many of which are not detectable to passengers. Although Amtrak will reveal few specific details about its efforts, Dan Stessel, spokesman for the company's Northeast Corridor, says Amtrak is conducting additional patrols of stations, railcars, and tracks, using officers from its own 300- to 400-member police force as well as bomb-sniffing dogs. It has also beefed up the police presence at some stations across its system and continues surveillance of key stations and portions of 22,000 miles of tracks via motion sensors and closed-circuit television monitors.

In response to March 11, Department of Homeland Security secretary Tom Ridge announced that the agency would test a baggage- and passenger-screening system this summer at a station in New Carrollton, Maryland, that serves both Amtrak and commuter passengers. The Transportation Security Administration stresses that at this point there is no plan to implement an extensive, multi-layered system similar to the one used for aviation security. But at a minimum, rail passengers in the United States might soon be required to pass through a metal detector or some other type of screening device before boarding. The pilot program is expected to be in place by early summer.

The emphasis will probably be on detecting explosives rather than authenticating passengers. (Currently, Amtrak riders need to show only a photo ID to purchase a ticket from an agent—and those using automated kiosks needn't show identification at all.) One reason: the main threat is terrorists planting bombs, not turning trains into weapons. "Your hijacking options are slim," Stessel notes. Even if someone did commandeer a train, he wouldn't have complete control of it, since some tracks are coded for speed and the brakes would kick in if the train started to go too fast at certain points on the track.

For the Europeans, whose rail networks are more heavily used, security has been on the agenda for some time. Eurostar has had X-ray scanners in place since it launched service a decade ago. Last December, the International Association of Public Transport recommended that the European Commission develop ways to assess the security risks to the Continent's mass-transit systems, including trains and subways. The IAPT also called for increased security training and the standardization of security practices.

In early March, before the Madrid bombings, when France received credible threats against its rail lines, 2,200 inspectors were dispatched to search 18,000 miles of tracks, a task that was accomplished in 2 1/2 days. After March 11, the British increased their usual announcements about unattended bags, and many countries, including France and Spain, ordered soldiers and police to patrol train stations.

Despite the very real difficulties of securing the world's rail networks—metal detectors and X-ray scanners won't catch all explosives, and it's practically impossible to prevent bombs from being planted along hundreds of thousands of miles of tracks—one silver lining of the Madrid bombings is the new attention the subject has received. After DHS secretary Ridge announced the pilot rail security program, for instance, the Senate Commerce Committee passed a $1 billion security measure for the nation's rails and public transport systems. (The federal government spent $9.6 billion on aviation security last year.) The House was likely to approve a similar package. This is an encouraging development. For as Amtrak's business rebounds—this year, the company recorded its best February and March ever in terms of ridership—and other train systems expand around the globe, the safety of riders is one issue that cannot be ignored.