More than half of the delays on the Los Angeles County passenger rail network last year were connected to problems with Metropolitan Transportation Authority train cars, a new audit has found.

Of the 2,585 reported delays on Metro trains last year, 55% were caused by malfunctions of the rolling stock, including problems with brakes, doors and speed-monitoring systems, according to an audit prepared by the Wathen Group, a consulting firm. Mechanical delays were particularly prevalent on Metro’s four light-rail lines.

Many of Metro’s light-rail cars are at least two decades old and have not received the intensive overhauls that are recommended after 15 years of service. The agency’s decision to skip those overhauls has created more problems now, officials said Thursday.

“It’s not the fact that we’re not maintaining the cars well,” said Conan Cheung, a deputy executive officer, at an agency committee meeting. “We’re trying to catch up, due to … decisions made in the past.”

Read the full story on LATimes.com.