Washington (CNN) -- Two U.S. senators from Maryland are expressing concerns that a year after a deadly commuter train wreck near Washington there are still safety problems in the transit system known as Metro.
Nine people died and more than 70 were hurt June 22, 2009, when an afternoon commuter train collided with a parked train on the same tracks near the border between the District of Columbia and the Maryland suburbs.
Sen. Barbara Mikulski told reporters at a news conference in the U.S. Capitol on Monday that "in the last 12 months, there have been 13 Metro deaths and even more accidents," that demand a continued effort to replace old hardware and create a safer working environment.
Fellow Democrat Sen. Benjamin Cardin said they want Metro officials to know "we won't tolerate a system that does not place safety as its top priority," expressing concern that "more needs to be done," including a federal role in establishing safety standards.
While acknowledging a need to expand service to suburban commuters, Cardin said, "I must tell you, our highest priority is to make sure that the current service is done in an effective, safe way."
In response, Washington Metropolitan Area Transit Authority spokeswoman Lisa Farbstein told CNN in a written statement that officials have learned to "seek out best practices and reassess, and that is exactly what we have been doing to establish a new, stronger safety culture."
But leading up to the accident, "Metro didn't have the manpower to implement a safety program," Mikulski noted, saying she found it "shocking" that officials with the transportation authority "didn't have any safety standards; they didn't even have a checklist for change."
Mikulski has authored pending legislation to establish federal safety standards for transportation systems such as Metro, and has connected continued federal subsidies with the implementation of improved technology.
She said her bill insists that "Metro develop the metrics for actually measuring safety improvements and reporting quarterly to Congress" and the Department of Transportation.
"No more lip service; real service, measured in real time, to get real results," Mikulski said.
Cardin suggested human failures remain part of the safety risk. "We have to change the culture within the Washington transit system, to make sure that they place safety as their top priority," he said.
Federal accident investigators had cited persistent delays in taking older transit cars out of service, despite long-standing recommendations that the cars are less safe in a collision. Metro had said it didn't have enough money to replace all the cars with newer models.
The National Transportation Safety Board, investigating the accident, said there were unreliable sensors in the track that were supposed to warn train operators about stopped rail cars in the path ahead.
In one test last year along the accident scene, a rail car parked around a curve was not detected by the system on a train that followed.
The transportation board's chairman, Deborah Hersman, in a written statement issued Monday, said her agency "remained on scene for 6 weeks examining the signal system to find out how it malfunctioned -- by far the longest on-scene rail investigation in its history."
Hersman said the board expects to issue a final report on the accident next month.
Although the board's recommendations are advisory, Mikulski's bill would grant federal transportation officials the authority to implement such changes.
She told reporters, "We're going to take these national safety standards and take them out of the advisory book and put them in the federal law book and in the federal checkbook" as part of budget legislation.