"Perhaps more than any other sector, adaptive measures undertaken in transportation will emphasize capitalizing upon the opportunities afforded by climate change."⁽²²⁾

The Canadian transportation sector has invested in a large number of adaptive measures to accommodate current climate and weather variability. Many of these responses, intended to protect infrastructure, maintain mobility and ensure safety, involve significant expenditures but result in a robust system that is able to accommodate a wide range of conditions, as currently experienced. Transportation systems, however, represent long-term investments that cannot be easily relocated, redesigned or reconstructed. Thus, there is a need to be forward looking and to consider not just our recent past, but also our near and longer term future.

Under a changed climate, the nature and range of adaptive measures would likely change, with costs increasing in some areas and decreasing in others. However, current literature suggests that the risks will be manageable, with appropriate forward planning. Nevertheless, at this time, there is little evidence that climate change is being factored into transportation decisions. The following discussion provides examples of current practices, innovations and potential adaptations that may reduce vulnerability related to climate change. The discussion focuses mainly on planned, rather than reactive, responses.

Design and Construction Standards and Practices

Weather sensitivities are reflected in design and construction standards and protocols. No matter what the form of infrastructure, new or existing, the transportation planning process should consider the probable effects of climate change, potentially building in more resilience to weather and climate.

For coastal areas threatened by sea level rise and storm surges, adaptations may include relocation of facilities and redesigning and/or retrofitting structures with appropriate protection (see Coastal Zone chapter). One example of where this has occurred is Confederation Bridge, which links Prince Edward Island to mainland New Brunswick. In this case, a one-metre rise in sea level was incorporated into the design of the bridge to reduce the potential effect of global warming over the estimated 100-year life of the bridge.^{(65, 66)}

For asphalt-surfaced facilities, such as roads and airstrips, temperature variations are currently considered in the selection of asphalt cements (and asphalt emulsions for surface-treated roads). The intent is to minimize both thermal cracking under cold temperatures and traffic-associated rutting under hot temperatures. To accommodate warmer summers in southern Canada, more expensive asphalt cements may be required, because materials used in roadways have a limited tolerance to heat, and the stress is exacerbated by the length of time temperatures are elevated.⁽²²⁾ Although there may be associated costs, this could be accommodated at the time of construction or reconstruction. Changing patterns of freeze-thaw damage are more difficult to plan for, but innovations related to design and construction may reduce current and future vulnerability of Canada's road network. For example, research conducted by the National Research Council is addressing ways to reduce heaving and cracking of pavement around manholes.

For transportation and other structures built on permafrost, a number of lessons have been learned over the past century. For example, failure to incorporate appropriate design techniques and regularly maintain the rail line between The Pas and Churchill, Manitoba in the early 20th century resulted in significant damage, as subsidence and frost heave twisted and displaced some rail sections.⁽²⁷⁾ Today, although construction over or through permafrost is based on careful route selection, most decisions do not account for future climate change, due in part to insufficient availability of data and maps (see Box 3). There are, however, several options that are used to improve the longevity of infrastructure built on permafrost. For example, polystyrene insulation was placed under one part of the Dempster Highway near Inuvik,⁽²⁷⁾ and the Norman Wells pipeline, in operation since 1985, has many unique design features to minimize disturbance in the thaw-sensitive permafrost. Another possibility is to construct temporary facilities, which can be easily relocated (e.g., reference 67). Again, these practices have associated costs, but they illustrate that capacity exists to deal with variable climate in a highly sensitive environment.

BOX 3: Route selection in permafrost regions⁽⁶⁸⁾

Higher temperatures are expected to decrease both the extent and thickness of permafrost in the Mackenzie Valley, as well as increase the temperature of the permafrost that is preserved. All of these factors could compromise the reliability and stability of transportation routes and other engineered structures. Most permafrost maps do not contain sufficient information to address the relationship between climate change and permafrost. In this study, researchers used models to define the associations between changing climate and ground temperatures. Work is now underway to apply these modelling approaches to high-resolution (<100 m) spatial data for the Mackenzie Valley in support of transportation decision making, including selecting potential new road and pipeline routes. Model results showing distribution of permafrost in a portion of the Mackenzie Valley under equilibrium conditions of baseline climate (left) and a warming of 2°C (right). larger image [JPEG, 50.6 kb, 467 X 210, notice]

There are also innovative approaches for dealing with short or uncertain ice-road seasons. Possible adaptations include increased reliance on barge transport during the summer; more expensive construction and maintenance of ice roads that would extend their seasonal life (e.g., construction of permanent stream crossings); the construction of all-season roads; and other innovations, such as the recent decision to transport oilfield equipment over ice roads in the Canadian Arctic and Alaska with the assistance of balloons.⁽⁶⁹⁾

In terms of inland shipping, it may be appropriate to design wider or deeper locks than would be warranted under the present climate, since it is easier to design for climate change than to do a retrofit. Another alternative for the Great Lakes-St. Lawrence Seaway system would be to invest in vessels that require less draft. Dredging is a common response to low water levels (reference 70; see also Coastal Zone chapter) and was used extensively to manage recent (2001) drought impacts, although some researchers have identified concerns over the disposal of contaminated sediment.⁽⁷¹⁾

Both the full effects of climate change and the service life of many forms of transportation infrastructure will be realized over decades, rather than years. It is therefore important that applied scientific research be undertaken to help ensure that infrastructure that is replaced or retrofitted realizes its full service life.

Information Systems

Transportation managers use advisory, control and treatment strategies to mitigate environmental impacts on roadways. Each of these requires detailed site-specific information, often in real time. Information on atmospheric and other physical conditions may be integrated with Intelligent Transport Systems (ITS), such as automated traffic-control and traveller-advisory systems, to address transportation challenges. Throughout the developed world, governments are investing hundreds of millions of dollars in ITS, with a view to improving mobility and safety and also reducing maintenance costs. One example of a weather-specific information system is ARWIS (Advanced Road Weather Information Systems), which is used primarily for winter-maintenance decisions. For example, the Ontario Ministry of Transportation uses information from 39 ARWIS monitoring stations to monitor and predict road and weather conditions, and reduce the use of salt on roads.⁽⁷²⁾ Another example is the use of the Automated Identification System (AIS) for navigation, which is used to transmit information between ships and between the shore and ships. This information can include data on water levels, wind speed and ice conditions, as well as safety-related messages (e.g., reference 73).

From a climate change perspective, there is a need to help steer the development and implementation of information technologies so that mobility and safety benefits will be maximized under future, as well as current, conditions.

Shifts to More Resilient and Sustainable Systems

There is increasing support for moving toward a more sustainable transportation system in Canada, one that would add environment and equity to existing priorities of efficiency and safety.⁽⁷⁴⁾ Fortunately, many initiatives that are consistent with sustainability principles not only facilitate the reduction of greenhouse gas emissions, but also increase resilience to potential climate change impacts. These may include the adoption of selected new technologies and best-management practices, as well as changes in travel patterns that reduce exposure to risk. For personal mobility, promising examples include encouraging information-sector employees to work from home (telework); changing land-use patterns to shorten commutes and increase accessibility to goods and services; and providing financial incentives to use transport modes that are inherently safer and more reliable, even in the face of a changing climate.