The bombings on Madrid’s rail lines on March 11 that killed 191 and wounded 2,000 highlighted a stark reality long known to security experts. They say protecting ground transportation from terrorism is a task that will require billions of dollars, innovative approaches, years of effort, accelerated research–and ultimately will be only moderately effective.

Achieving even acceptable risk will "require a lot of ingenuity from our engineering community," says Edward Badolato, executive vice president for homeland security in The Shaw Group’s Washington, D.C., office. "We are in a situation where we have to do better."

Doing better will be a big challenge. In New York City, commuter lines and subways handle 5 million passengers on an average weekday, with roughly 350,000 passengers passing through Penn Station alone. New York’s subway system has 468 stations–all with multiple access points.

Nationwide, security planners are faced with vetting tens of millions of passengers every day and correcting an almost infinite number of structural vulnerabilities. "Trains, subways and buses are the new arena for terrorists concerned with body counts and willing to kill indiscriminately," says Brian Michael Jenkins, director of the National Transportation Security Center at Mineta Transportation Institute, San Jose, Calif.

Congress is reacting. In April, the Senate Commerce Committee cleared a measure authorizing $1.2 billion to tighten security on passenger and freight railroads. On May 6, the Senate Banking Committee approved a bill providing $5.2 billion for transit security, including $3.5 billion for capital projects. The American Public Transportation Association pegs security needs at $6 billion and seeks $2 billion of that for 2005 (ENR 5/17 p. 11). But the House is moving slowly.

The main problem is how to secure transit and inter-city rail and maintain their roles as convenient, inexpensive and accessible ways to travel in and between congested cities. "New York’s Penn Station is one square block and it handles more passengers each day than all three New York airports combined. How do you secure an area like this?" asks Amtrak spokesperson Dan Stessel.

Tom Ridge, secretary of the Dept. of Homeland Security (DHS), hopes new technology may help. "It’s conceivable, since everybody ultimately goes through a portal, that there might be a device or devices that we might be able to deploy as people enter the system," he says. OnMay 4, DHS began a 30-day test to screen baggage for explosives at Amtrak’s New Carrollton, Md., station. Many see this as little more than a data-gathering exercise because the cost and delays associated with airline-type security make it impractical for transit. It also could push people back into their cars. With nearly 43,000 U.S. highway deaths in 2003, that would displace one risk with another with "no net security benefit to the nation," says Jenkins.

DHSon May 20 issued mandatory directives for transit and inter-city rail lines that include removing some trash containers and designating coordinators to improve communications with federal officials. "These protective measures, along with others already in place, advance our mission to ensure rail passengers are protected," says DHS Under Secretary Asa Hutchinson.

Airline security focuses on deterrence, while mass transit emphasizes minimizing casualties and quickly restoring service after an attack. With this in mind, U.S. cities are conducting vulnerability assessments in order to set priorities. "This month, we will begin issuing contracts to shore up our infrastructure," says Tom Kelly, spokesperson for the New York Metropolitan Transportation Authority. "We have $590 million to spend in addition to a $300-million budget for fences, barricades, barriers and quick constructions."

The New York City office of Hinman Consulting Engineers, a design firm specializing in blast-resistant buildings, has done blast evaluations at Grand Central Terminal, Penn Station, Triborough and Verrazano Narrows bridges and Queens Midtown Tunnel. "The goal is to prevent structures from falling down on people," says Nanci Buscemi, Hinman structural engineer. While there always will be a weapon bigger than engineers design for, structural hardening and other steps are effective, cost-effective and doable, she says. "In some cases we recommend an imposed standoff using perimeter barriers, or construction of an architectural element around...