When describing his transit plan, John Tory loves the word "bold."

The promise is that his rail proposal - a mix of new and existing infrastructure with 53 kilometres of track connecting 22 stations - is the quickest and cheapest way to tackle congestion and take pressure off the subway system. But as his front-runner status brings closer attention, there are growing questions about his proposal.

After weeks of criticism of the plan's financing model, its impact and technical challenges are prompting increasing attention. This week residents of a west-end area went public with concerns about the line's effect on their neighbourhood. Also this week, Mr. Tory promised not to interfere with homes or parks, which raises the prospect of a lengthy tunnel.

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How long remains to be seen. The Tory camp will not say, so a Globe and Mail reporter went the length of the proposed new spur along Eglinton with an altimeter and a stack of maps to make a preliminary estimate. Based on the elevation changes, restrictions on the gradients trains can handle and the limited amount of surface area available for above-ground rail, it appears the tunnel would have to stretch more than 8 kilometres. Mr. Tory disputed that figure, and said he remained confident their budget is enough for the project.

There are also other problems. Carrying the riders he is projecting at the frequency promised would require trains far too long for existing stations. And increasing the number of trains raises costs and risks overloading the rail corridors.

His proposed line runs along the Kitchener and Stouffville GO rail corridors, both of which the province is planning to electrify, and is promising 15-minute service. These would be GO trains but would be branded differently.

He is also proposing a dozen additional stations on those lines and about 12 kilometres of new tracks along Eglinton West, with another four stations there.

He packages the whole thing under the name SmartTrack and says it will cost $8-billion. The province and Ottawa will be expected to kick in two-thirds, with the city borrowing to pay the rest.

This line forms the centrepiece of his campaign and, in a race dominated by transit and gridlock, it has helped propel him into the lead. As the presumptive candidate to beat in this election, Mr. Tory's plan deserves the closest look.

The tunnel



The plan was pitched as a surface subway and Mr. Tory said during at least one debate that no tunnelling would be required. In recent weeks, though, he acknowledged that some of the line would have to go underground.

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The stretch in question is a spur that runs from Mount Dennis, around Eglinton and Weston, to the Airport Corporate Centre in Mississauga.

Along the route are residential neighbourhoods, parks and other green spaces and parts of an old right-of-way that was set aside for a highway that was never built. How to get a heavy rail line through this area has been the focus of a drumbeat of attacks by mayoral rival Olivia Chow.

Going underground allows the Tory camp to allay the concerns of local residents and takes the air out of Ms. Chow's criticism that the train will somehow have to make a sharp turn. But they will not be specific about how much tunnelling will be needed, saying they have not done the required engineering studies.

However it is possible to draw an educated conclusion. Mr. Tory has said he won't demolish homes or run surface rail through parks, so you cross off those areas. You can eliminate places where development is pending. The rail corridor will have to be at least 30 metres wide, so any open space more narrow than that is also out. After that it's simple math. Metrolinx standards are that their trains cannot go up or down at greater than a 2.5-per-cent angle, a common passenger rail restriction.

One can use that gradient to calculate the amount of lateral distance required for the train to change elevation along this stretch, which falls and rises sharply. That result, in turn, allows you to work out the earliest place the train will be able to surface.

This process suggests that, if the train goes underground at Mount Dennis, it cannot come above ground until just west of Martin Grove. It would emerge about 8.5 kilometres from the rail corridor where the tunnel began

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In a visit this week to The Globe's editorial board, Mr. Tory appeared surprised by this figure, but did not offer his own.

"I'm certainly led to believe that the tunnelling required is less … and I guess there's maybe just a respectful disagreement," he said.

Using the transit rule of thumb of $300-million per kilometre, a tunnel that length would cost $2.55-billion and soak up nearly one-third of the total budget.

After Martin Grove there are other problems. Emerging on the north side of Eglinton would force the train to cross nine lanes of traffic, near ramps for Highway 427.

Having the tunnel end on the south would mean the tracks coming out on top of a walking and bicycling trail. Either option would mean having to cross Mimico Creek, the 427 and the East Mall and then traverse a residential neighbourhood.

Pushing the tunnel exit further along would mean having to drop it down under Mimico Creek. Coming up in the next open space along the route would add nearly two more kilometres of tunnelling. Mr. Tory says that they have budgeted for the required tunnels but won't reveal a breakdown of the costing. Not only is tunnelling disruptive to the neighbourhood while under way, it's hugely expensive.

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The size of the trains on this line means that the boring machines used on the Eglinton Crosstown LRT are too small and cannot be re-used. And finding space for the big launch shaft required to begin tunnelling could prove challenging.

Ridership



Another issue is the size of the trains that would run on this line.

The Tory camp predicts it will carry 200,000 passengers a day. They say about one-third is expected to come by persuading people to switch to transit, which would require the neighbourhoods served by the line to rise to the city-wide average for transit use.

The rest is projected to come by diverting current transit users to the line, with the campaign saying its figure is based on data from other cities and on "common sense."

Should those projections come true, it would pose difficulties.

If the ridership were spread evenly around the clock, that would mean more than 8,000 passengers per hour. With 15-minute service, that would require four 14-car trains every hour, whereas the longest GO now runs is 12 cars. Such trains could not fit at current Toronto GO stations, which are limited to 12 cars.

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And if the ridership is distributed unevenly, according to standard transit demand patterns, the peak hour total would be around 12,500.

This would require four trains stretching 21 cars each, meaning stations would have to be enormous.

In a technical briefing, the Tory camp repeatedly promised 15-minute service, never suggesting the trains could run more often. In any event, trying to reduce train size by having more of them would push up costs and create new problems of capacity in what will be crowded rail corridors already. An eventual switch that the province has planned to electric multiple units (EMUs) is not expected to result in trains with greater capacity.

As the front-runner, Mr. Tory has tended to deflect pointed questions about his plan by saying simply that he's sure it can work. He likes to cite engineering challenges during the digging of the Yonge subway as evidence that problems can be surmounted. And he has dismissed critics as people who always find a way to say 'no' to something.

"I'm just confident that the plan is sound, the partnerships will come about, the financing will work for this project," Mr. Tory said this week. "It's going to work and I'm going to make it work. I have the determination to get this done."

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