\r\nThe GAO found that freight and commuter railways continue to face significant challenges in implementing PTC, and that most railways interviewed would need one to five years to complete implementation. The report also states that Federal Railroad Administration (FRA) management of implementation was insufficient to properly monitor individual railways' progress, and the GAO recommends that the FRA improve its supervision by developing a plan to hold railroads accountable for making progress on PTC.\r\nThe report was requested by committee leaders from the Senate and House of Representatives, including House Transportation and Infrastructure Committee chairman Mr Bill Shuster and Senate Commerce, Science, and Transportation Committee chairman Mr John Thune.\r\n"This report confirms that the PTC mandate is not achievable, and extending the deadline is essential to preventing significant disruptions of both passenger and freight rail service across the country," Shuster says. "I am committed to working with Senator Thune and our colleagues to address the clear need for an extension, and to ensure that railways implement this important but complicated safety technology in a responsible manner."\r\nThune added: "Passenger and freight railways need time beyond the current deadline to finish implementation of a complex system that relies on new technology. Failure to extend this legal deadline would create significant hardships for customers and passengers who rely on rail. Passing an extension that includes meaningful accountability for PTC implementation is the best thing Congress can do to enhance safety and avert a chaotic situation that would hurt our economy."\r\nIn 2008, Congress passed legislation requiring the installation of PTC on all freight railways carrying certain hazardous materials, as well as all lines carrying passengers. This gave the railways little over seven years to roll the technology out over nearly 100,000 route-km.\r\nAccording to the GAO report, railroads have faced numerous challenges in meeting the deadline, including:\r\n\r\nThe need to design, produce and install over 20 new major components\r\nA limited number of manufacturers for those components\r\nMultiple phases of testing and system integration\r\nAttempting to meet the current deadline before defects have been identified and addressed\r\nDifficulty in obtaining radio spectrum and Federal Communication Commission (FCC) permits for communications infrastructure\r\nDelays in approval of safety plans by regulators; and\r\nThe complexity of achieving interoperability among varying types of PTC systems \u2013 even those railways that complete installation of PTC on their own lines by December 31 will continue to face interoperability issues with other railways.\r\n\r\nThe Senate included an extension of the PTC deadline in transport legislation passed earlier this year, but the Obama administration has also found the deadline to be unworkable and has requested an extension.\r\nEarlier this month, the chairman of the Surface Transportation Board noted in a letter that a failure to pass a PTC extension could create service issues for rail customers.\r\nAssociation of American Railroads president and CEO Mr Edward Hamberger said on September 16 that the GAO report confirms what freight and passenger railroads have been saying for years: Congress needs to extend the PTC deadline."The GAO report reinforces the railfreight industry's contention that PTC is an extremely complex technology that requires more time to install and test safely," Hamberger says. "Railfreight operators have always contended that the congressionally-mandated 2015 deadline for having PTC fully functional and being used coast-to-coast by passenger and freight alike was not realistic. The fact that can't be ignored is that time is quickly running out for taking action to extend the deadline and avoid the dire consequences of not doing so."\r\nHamberger warns that there is a risk of service shutdowns and major disruption if Congress fails to extend the deadline by the end of October.\u00a0"Railways are beginning to notify their customers of the possibility of an impending rail shutdown as they, too, have to prepare for such a worst-case scenario," he says. "Congress can't wait until November or December when the clock is about to run out. If lawmakers want to avert massive disruption it must take action now to extend the deadline."\r\nAccording to the AAR, the industry has so far invested more than $US 5.7bn in PTC implementation.