TTC boss Andy Byford said Thursday he doesn’t want to keep making apologies for service problems, but said the subway system needs significant upgrades or delays like the one riders experienced Wednesday are likely to get worse.

Byford appeared on CBC Radio’s Metro Morning on Thursday, one day after he had to personally say sorry for "horrendous" delays faced by subway riders during yesterday's morning commute.

The delays prompted Byford to deliver a personal message over the TTC public address system saying: "Ultimately I am responsible and I apologize without reservation."

Byford also went to Bloor subway station in person to apologize to riders.

Byford told host Matt Galloway that problems with the subway’s signal system — which was installed in 1954 — led to the problems.

Byford said the electrical current that feeds the signals began to drop "quite dramatically," just before 8 a.m.

"We had to introduce a special way of working to keep trains safety apart," he explained to host Matt Galloway. "That means you’ve got to slow the service down, there’s big gaps between the trains, that’s why the service was all blocked up, back as far as Finch."

Byford said he was at Bloor station between 8:30 and 10 a.m. when the delays were at their worst.

"I saw for myself how angry people were," he said. "I don’t want to keep making apologies, but I felt it was warranted yesterday, based upon the service we gave to people."

Many riders complained that information about the delays was not communicated to them as they sat — or stood — on crowded, stationary trains.

Byford said transit control and many operators were "pumping out information," but conceded that communication about system delays must improve.

"I would dispute that there was no information," said Byford. "But if customers are saying it wasn’t good enough, that counts for a lot with me, I will continue to try to improve that."

Galloway asked Byford about the infrastructure problems the TTC is facing. Weekend closures on the Yonge-University-Spadina line are often devoted to signal work.

"We’re going to have to replace that signaling, it won’t be easy to upgrade, but until and unless we replace that signaling, the system will become increasingly unreliable," said Byford.

As an example of why the upgrades will be so difficult to carry out, Byford said old track between Davisville and St. Clair stations on the line needs to be replaced before the signals are upgraded.

"It’s original track, replacing it won’t be easy," said Byford. He added: "it is pointless installing a brand new signal system on worn-out track."

Galloway asked if this would require shutting down the line for repairs.

Byford’s response: "At some point, we will have to do that."

Signal problems also caused problems during Thursday's commute, slowing trains between Kipling and Runnymede stations on the Bloor-Danforth line.

Galloway also asked Byford at what point to people would start to tune out apologies from TTC brass. A similar apology was issued in March after another difficult commute.

"The last thing I want to do is keep making apologies," said Byford. "I think they lose their impact. For me yesterday was bad enough to warrant my personal apology. I do hold myself accountable for these things.

"I knew when I took on this job there would be some bad days before it got better."