Although they account for only 8% of the total stock of public assets, bridges and overpasses are critical to the nation's overall economic health.

This fact was highlighted in September 2006 by the collapse of a highway overpass in Laval, Québec. When it collapsed, two people died, several were injured and commuter and goods transport in the area was delayed for several months.

According to Statistics Canada, bridges and overpasses in the country are the second-oldest of the five major categories of infrastructure, having passed 57% of their useful life of 43.3 years. Moreover, over the past ten years, despite a significant increase in overall spending on government infrastructure, the average age of bridges and overpasses has trended gradually higher from 22 years (52% of service life) to 24.5 years in 2007 (57% of service life).

From a regional perspective, it is worth noting that at 31 years (72% of service life), the age of the stock of bridges and overpasses in Québec is well (+26%) above the national average. Nova Scotia has the distinction of having the country's second-oldest bridges and overpasses, at 28.9 years (66% of service life).

With the exception of Prince Edward Island, where the massive investment on the Confederation Bridge caused the average age of its bridges and overpasses to drop sharply, the age of bridges and overpasses in the rest of the country is not significantly different from the national average.

Looking ahead, the fact that the average age of the country's bridges has trended higher in all but two provinces over the past 10 years indicates that governments at all levels need to invest more in bridge and overpass maintenance and repair. Failure to do this increases the risk that we will see more bridge failures like the one in Laval in the future.