Annoying commutes are nothing new to TTC riders. But Nov. 5 stands out as a particularly heinous morning, as subway signal failures in two locations consigned passengers to shuttle buses for about three hours.

This is what a generation of under-investment in transit looks like, explained apologetic TTC officials, citing the 1954 signal system still in use on the subway as the culprit.

The good news, they added, was that a $562-million upgrade is underway — a system called automatic train control (ATC) that will replace the old block signals on the TTC.

But commuters, who have been told ATC was in the works for the past seven years, will have to wait another five to reap the benefits.

Other systems, including London, that have done similar signal modernizations have found they take 10 years.

When provincial funding for the new computerized system was first announced in 2007, it was projected to be a five-year project. But 2012 has come and gone. The completion date was revised to 2016, and then again, to 2018.

TTC officials are now suggesting 2020 is more realistic.

“It’s just taking longer than anticipated. This is the problem with dates. When we announce dates they can move,” said TTC spokesman Brad Ross.

In the case of ATC, previous timelines were simply inaccurate, particularly as the project has grown significantly and proved more complicated than was earlier imagined, said TTC spokesman Brad Ross.

When the TTC set out to modernize its old block signal system the project was far less ambitious. It was only going to replace the 1954 signaling system on the oldest part of the subway, between Eglinton and Union.

About a year later, the TTC decided to upgrade the signals for the entire Yonge-University-Spadina line.

In 2009, the long-awaited subway extension to York Region finally broke ground — but there was no funding to build ATC into the new stations, so the project grew again to include the six new stops.

The work has to be done accurately because there comes a point of no return. Once ATC is activated, there’s no going back, said Ross.

The TTC’s existing system shows transit controllers where a train is located within an area of tunnel known as a block. When a train passes over a particular location on the track, it triggers a signal change. For safety, only one train can be in a block at one time. When the train exits the block, it sends the signal that another train can safely enter that section of tunnel.

ATC is a telecommunications-based system. Computers control the train’s speed and distance from the next train, maintaining a safe distance between the vehicles.

This means trains can run closer together. The TTC will be able to increase its subway “throughput” by 25 per cent, running trains on two-minute headways instead of 2.5 minutes in the peak, with a commensurate increase in rider capacity.

Meantime, however, the moving parts of the 60-year-old signaling system are breaking down, hindering the subway’s reliability.

Loading... Loading... Loading... Loading... Loading... Loading...

There will also be more weekend subway closures required to accommodate the ATC installation. The two-and-a-half- hour window when crews can work at track level at night is so brief that “a weekend is invaluable in terms of getting work done,” said Ross.

“Once the work is done, once we’re finished this, we will be able to extend subway hours. We can’t do that today on a regular basis because we need to do the work,” he said.

It’s likely the TTC will decide on a schedule of closures in January. The weekend closures are finished for this year.

An ATC timeline

2007 Metrolinx announces it will give the TTC $424 million for an ATC project to be completed in five years

2008 The TTC says the Yonge-University-Spadina line will have ATC by 2016. The Bloor-Danforth subway will have to wait until the 2020s

2009 TTC says in March that the contract for ATC will be awarded in April, to be finished in 2016.

2013 The TTC promises completion of ATC by 2018

2014 TTC says ATC on the Yonge-University-Spadina line will be complete by 2020, at a cost of $562 million.