WASHINGTON - U.S. commuter and freight railroads may be forced to suspend service or face daily fines beginning Jan. 1, unless Congress extends its year-end deadline for implementing new safety technology, lawmakers were told on Wednesday. The top U.S. railroad regulator said fines would apply for each violation after the Dec. 31 deadline to implement a technology that can automatically slow or stop a train, called positive train control, or PTC. The National Transportation Safety Board estimated that more than 245 people have died and 4,260 have been injured in preventable accidents since it began calling for PTC in 1969. Accidents the agency said PTC would have prevented include the deadly Amtrak derailment in Philadelphia on May 12. “Fines will be based on (our) PTC penalty guidelines, which establish different penalties depending on the violation. The fines may be assessed per violation, per day,” Sarah Feinberg, acting administrator of the Federal Railroad Administration, said at an oversight hearing in the House of Representatives. “Our ultimate goal is to bring all railroads into compliance as quickly, and as safely, as possible.” Federal regulations list 61 fineable PTC violations totaling $485,500 to $815,500, depending on whether they are deemed “willful.” Officials said violations could multiply quickly if assigned to separate pieces of equipment or track. Seven years after Congress set its deadline in 2008, most U.S. railroads say they do not expect to meet it due to the complexity and high costs of implementation. Separate freight and commuter rail estimates show full implementation could cost the industry nearly $13 billion. Republican and Democratic lawmakers have said they would support an extension, and some have proposed a 2020 deadline. But no action has been taken, and Democrats say an extension should still include fines to ensure that railroads comply. Without an extension, railroads could be forced to suspend operations to avoid the financial liabilities of operating outside the law, industry officials said at the same hearing. “It may be that the path forward really does involve the cessation of service. We’re all looking at that,” said Frank Lonegro, a vice president at CSX Corp, the freight handler that operates a 21,000-mile network spanning 23 U.S. states. CSX expects full implementation by 2020. Donald Orseno, chief executive for Chicago’s Metra Commuter Railroad, warned lawmakers that service suspension would put an additional 300,000 commuters on the road in the Chicago area. Metra expects to implement PTC by 2019.