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‘Intersections will fail’ in peak hours when Metro LRT Line reaches five-minute frequency: internal emails

A Global News investigation is raising serious questions about what exactly will be the true impact on traffic around the Metro LRT Line in the future. Vinesh Pratap has the details in Part 1 of his series – Oct 13, 2020

A Global News Freedom of Information request has resulted in the release of never-before-seen details related to the Metro LRT Line.

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The line opened in September 2015, more than a year late, plagued by ongoing signal issues which resulted in major traffic delays. Since its opening, those waits have subsided, with three-car trains operating at 15-minute intervals during peak periods.

Read more: Edmonton continues to wait: Date to fix Metro Line LRT issues approaches

But new internals details, now made public, show what could happen if the trains run every five minutes, which will result in the crossing arms going down and up more times per hour.

Two years before it opened, the city commissioned an animation model. It shows significant traffic backup on 111 Avenue for vehicles travelling east on the corridor, with queues stretching more than 10 blocks; from 106 Street where the trains cross at surface level past 116 Street.

“Traffic modelling is just one piece of that really big overall puzzle,” Brad Smid, one of the city’s leads on the LRT expansion, said.

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Animation model of Metro LRT Line going through Edmonton – Oct 13, 2020

The FOIP request also yielded 14 pages from various emails — multiple sections were redacted.

However, in one email, written about two weeks after the line opened in September 2015, Smid wrote to unknown recipients about congestion issues “primarily around Princess Elizabeth and 106 Street.”

“If I recall correctly, the model showed that with 10-minute headways, the intersections had time to recover between pre-empt phases, but that in the future when we get to five-minute headways, the intersections will fail in the peak hours,” Smid wrote.

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Read more: ‘This is the end of the line for Thales’: Contractor fired from Edmonton’s Metro LRT Line

Smid addressed both the emails and the animation in an interview with Global News.

“So, where you might see wait times increase at very specific intersections. In fact, if you look city-wide, we’re actually improving mobility and improving travel times throughout the city,” Smid indicated, adding planners have to consider multiple variables when designing the LRT system.”

Internal City of Edmonton documents reveal potential future traffic congestion around Metro LRT Line – Oct 13, 2020

As for the concerns raised in the email about how the “intersections will fail in the peak hours,” Smid said: “What’s written there is an observation on a very specific analysis that was done. That’s not the whole picture.”

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Smid said the word “fail” indicates projected traffic volumes could be higher than the theoretical capacity of an intersection.

“There are some times where you might have to wait more than one light to get through, whether you’re on an LRT corridor or not. This happens at busy intersections all over the city,” he said.

“The city did plan the most direct route for the Metro Line between downtown and NAIT.”

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David Cooper, who runs Leading Mobility Consulting, works with transit agencies across Canada. The former Edmontonian is not involved with any city project, but is familiar with Metro Line operations.

“It’s a complex puzzle to put together in this particular piece, especially when you’re implementing that (LRT) in an area that didn’t originally envision it,” Cooper said.

Cooper said as service increases, “there’s changes to how you build the schedule to the LRT. There’s changes to how you build signal timings into a signalling system. So, it’s something (where) there’s many different versions and ways to look at this. I don’t feel the city will let it be in a situation where the intersections don’t function.”

Two years after the Metro Line opened, the city approved a new Crossing Assessment Framework which determines if trains should go above or below intersections.

Smid said the Metro Line hot spots were reassessed and deemed OK, including for future growth.

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“We are looking at traffic but we are also looking at, what type of city are we building and what type of LRT system are we building that fits into that city?”

In part 2 of our investigation Wednesday, we’ll have city hall reaction to the FOIP request, including some potential solutions being offered up should traffic congestion become a significant concern in the future.


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