The Chicago-area's Metra commuter railroad says it will miss a 2018 deadline for installing safety technology on all routes.
Metra is among the four commuter railroads and three major freight railroads that informed the federal government last week that they won't hit the target.
The technology known as positive train control uses GPS monitoring and automatically stops trains before an accident.
Metra expects to have some of its system operational in 2018. As allowed under federal law, it is seeking until sometime in 2020 to have the rest up and running.
Factors causing the delay include the $350 million cost. The mandate from Congress included almost no funding.
Also, the technology has to work seamlessly among railroads that share tracks, a particular challenge in Chicago, the nation's busiest rail crossroads.