Hey there, time traveller!
This article was published 5/11/2019 (636 days ago), so information in it may no longer be current.
Winnipegger motorists take note: your future looks black indeed.
After decades of relying almost entirely on concrete for road renewal — more than 85 per cent of all roads, regardless of use or capacity, currently feature concrete — there is a move afoot to update city policies to allow for broader application of blacktop.
You can already see the shift. This summer, the City of Winnipeg confirmed it had chosen asphalt — a mix of aggregate and bitumen — over the traditional concrete for the new Waverley Street rail underpass.
It revealed what has been a slow evolution in other high-profile city projects. The Chief Peguis Trail east of the Red River to Lagimodiere Boulevard was also completed without using a concrete base.
According to officials, this is a sign of things to come.
"We feel that we can (use more asphalt), and we're working towards that," said Brad Neirinck, city manager of engineering. "We're working away from just building primarily concrete (roads)."
Is the move good for motorists and taxpayers? That is a complex question with no easy answer.
Changing the major material used in road renewal involves a number of trade-offs.
Upfront, an asphalt road is about one-third less expensive than concrete and takes less time to build, Neirinck said. As well, repairs are less expensive and take less time to complete.
However, as always, there's a catch.
Neirinck said concrete lasts much longer than asphalt, and although repairs are more costly and time consuming, they do not need to be done nearly as often as with an asphalt surface.
The average lifespan of a concrete road is about 50 years, although Neirinck noted the city has some concrete streets that are almost 90, thanks to regular maintenance.
Asphalt roads, generally, have a lifespan of about 25 years, he said. That means although asphalt is less expensive up front, it has only about half the lifespan of a comparable concrete surface.
Repairs and maintenance — particularly for things such as potholes and rutting, which rarely afflict concrete roads in the earlier stages of their life cycle — must be done more often.
So, how will the city determine how much blacktop is in Winnipeg's future? There's also a catch on that point.
The city does not, at current time, have a firm policy on where and when to replace concrete with asphalt. A more formal policy is in the works, Neirinck said, but until then each new project will assessed on its own merits.
All in all, the city now finds itself in a bit of a road-surface limbo.
From quiet residential streets to the busiest regional routes, concrete still being poured. Despite choosing asphalt for the Waverley Street underpass, concrete was used for portions of Taylor Avenue and Waverley north of the grade separation.
Neirinck said asphalt needs a much deeper base of crushed rock that can, in some instances, interfere with underground wires, pipes and other sub-grade "structures" (as city engineers call them). In those instances where a thinner pavement structure is required, concrete will still be the product of choice, he said.
Also unclear is the long-term economics.
As is the case with all public infrastructure, there is always a trade-off between lower up-front costs and long-term costs. The city typically tries to deal with this challenge by performing a lifecycle cost analysis (LCCA), which is broadly applied to infrastructure projects where there are multiple methodologies or materials available.
According to a city report on pavement options, tabled last spring, the initial LCCA indicates "asphalt pavements have a lower initial capital cost and lower overall lifecycle cost."
However, the report noted there are other issues — including overall performance of the surface during that lifecycle — that need to be more fully explored.
In other words, in a city where complaining about the condition of the roads is considered a right and not a privilege, what kind of road do you get for that lower overall lifecycle cost?
The city is still working on a definitive answer.
Along with careful monitoring of existing asphalt streets in Winnipeg, Neirinck said the city is gathering information on the performance of provincial highways, the gross majority of which are asphalt.
As well, Ahmed Shalaby, Municipal Research chair at the University of Manitoba, will be helping to draft guidelines on where and when asphalt can be used over concrete.
If it performs just as well and is less costly, the move to asphalt makes sense.
All we need now is a more black-and-white policy (if you will) to guide the city into the future of road surfacing.
Born and raised in and around Toronto, Dan Lett came to Winnipeg in 1986, less than a year out of journalism school with a lifelong dream to be a newspaper reporter.