BROADWAY’S BIG BUDGET
Ministry talks extra costs associated with taking the SkyTrAin underground
The Ministry of Transportation has provided an explanation of sorts for the cost estimate of $500 million a kilometre for extending SkyTrain along Broadway in Vancouver.
The budget for the 5.7-kilometre Broadway Subway was estimated at $2.83 billion when Premier John Horgan greenlit provincial funding for the project earlier this month.
Presuming that number holds — count me as a skeptic — the subway would cost almost four times as much per kilometre as the Evergreen Line, completed just two years ago.
But the ministry says that is not a fair comparison.
“In order to compare the cost of the Evergreen Line with the Broadway Subway, both projects should be considered on the same time basis,” said the statement sent my way via email.
“If Evergreen construction was to start in 2020, the costs would need to be inflated by seven years. Given current market conditions and cost pressures for commodities and labour, if Evergreen were built today, it would have faced these same considerations.”
Seven years’ inflation at the current annual rate of 2.5 per cent would push Evergreen from the cost of $130 million per kilometre announced in 2016 to maybe $160 million. So inflation tells only part of the story, even allowing for a higher rate of increase for wages and materials.
The ministry says the remaining gap is accounted for by significant differences between the two SkyTrain projects. All six stations on the Broadway Subway will be constructed under ground, and “Underground stations are about seven or eight times more expensive than the above-ground stations constructed for Evergreen.”
As the name suggests, the subway will be mostly underground.
“Evergreen was 23 per cent tunnel and Broadway will be 85 per cent tunnel. A tunnel is two to three times the cost of an Evergreen-style elevated guideway,” said the ministry.
“It is not possible to build an Evergreen-style elevated guideway along Broadway due to constraints of existing adjacent property, guideway clearances at intersections, traffic requirements and the need for high-level stations.”
A third factor is urban versus suburban construction.
“Evergreen was in a relatively low density suburban area, compared to a very dense urban/commercial environment for Broadway,” says the ministry.
“On Evergreen there were limited utility relocations. On Broadway we estimate these costs to be in the region of eight to ten times higher than on Evergreen. Similarly traffic management and bus relocation costs will be significantly more.”
Then there’s land acquisition. “Property costs are very high along the Broadway corridor. High density commercial values have escalated significantly over the past couple of years.”
The public will have to wait to discover how each of the factors contributed to the budget estimate.
The government is withholding all cost breakdowns, per the “redacted” and “sanitized” version of the Broadway Subway business plan posted on the ministry website.
“To ensure a competitive procurement process and protect our negotiating position, some portions of the business case and other project documents must be withheld at this time,” the ministry stated.
“At the end of procurement a report will be released which will include the contract value and other cost information.”
The procurement process will play out over the next 18 months, with the final contract to be awarded in the winter of 2019. Even then, the ministry won’t release breakdowns for each item in the budget.
Not until the “end of construction” will “full details of final costs be released.” On the current plan, that would be in 2025, presuming no surprises and unexpected delays in the construction schedule.
The latter is a genuine possibility, given the inherent risks associated with tunnelling versus surface construction.
“Tunnel boring is risky business,” as B.C. Supreme Court Justice Christopher Grauer put it at one point during the lengthy legal proceedings arising out of construction of the Canada Line.
“Geotechnically, it cannot be predicted with certainty just what subsurface conditions a tunnel-boring machine will encounter until it gets there. In challenging conditions, tunnel-boring machines can get stuck and break down. If they do, and it is not a rare occurrence, that part of the project comes to a halt until the problem is fixed. Repair can be very expensive.”
“Just ask the good folks in Seattle,” he added, referring to the prohibitively expensive breakdown of the machine boring a highway tunnel under Seattle in 2013, which resulted in lawsuits and a multi-year delay.
This by way of the judge ruling it was defensible — for budgetary and scheduling reasons — for the Canada Line builders to have rejected tunnelling in favour of the less risky option of cut-and-cover construction through Cambie Street village.
Still, the punishing disruptions that cut and cover caused for businesses in the Cambie neighbourhood raised a cry of “never again” regarding any part of the Broadway extension. (It also generated a recent court award in favour of those businesses, but that is a topic for another day).
In short, while tunnelling is less disruptive on the surface, it comes with potential disruptions of its own for budgets and construction schedules.
The Evergreen Line had a six-month delay in construction owing to unexpected problems in the tunnelling phase.
With seven years to go before construction is completed, don’t be surprised if the big dig under Broadway ends up costing even more than the estimate of $500 million a kilometre.
A tunnel is two to three times the cost of an Evergreen-style elevated guideway.