AN INTENSIVE security network is to be installed on 13?km of line through Washington DC, used by Virginia Railway Express, Amtrak and CSX, under a $10m pilot project being promoted by the US Department of Homeland Security.CCTV cameras will send live images to law-enforcement agencies and provide a permanent record of any incursion. Intrusion sensors will trigger flashing lights and broadcast a recorded warning. Trains will also be scanned for identification to determine whether they are leaking toxic or radioactive substances. If the tight security ring proves successful, DHS officials hope to expand the system nationwide. But it is not clear what criteria are to be used to measure success. Nor is there any indication of the likely costs and benefits of a national roll-out.