The transportation sector module of ClimateData.ca provides easy access to important climate datasets, relevant resources, and case studies demonstrating the use of climate data in adaptation efforts for the Canadian transportation sector. This section explores potential climate impacts on the transportation sector from freeze-thaw cycles and temperature and precipitation extremes. Associated case studies demonstrate how both transportation infrastructure and operations can be adapted to withstand the impacts of climate change.
Weather impacts all modes and facets of Canadian transportation systems, and changes to average and extreme weather and variability caused by climate change will exacerbate these impacts. Canadian transportation systems should therefore be designed, constructed, and maintained with future climate variability and change in mind. Providing transportation experts from diverse backgrounds (e.g. engineering, government, industry, academia) and transport modes (road, rail, marine, air) with access to reliable and sector-relevant climate information is crucial for fostering climate resiliency and helping to inform adaptation action in the transportation sector.
The case studies highlighted in this module are largely focused on the use of climate data to inform climate adaptation in the roads sector. Roads represent a significant proportion of transportation infrastructure, and road practitioners also represent a large user group for this module (65% of respondents to a survey during stakeholder engagement for the development of this module worked in the roads sector). The construction and maintenance of roads also has high economic impact, and it is perhaps for this reason that the roads sector has the most accessible examples of leadership in climate adaptation, thus far. However, the key lessons learned in the use of climate data to inform adaptation are broadly applicable across transport modes. Submissions of examples of climate adaptation in other modes of transport, for future inclusion on ClimateData.ca, are welcomed and encouraged, and can be provided in the Feedback section.
Examples of climate impacts affecting the various transport modes are explored below. Users are also directed to explore the Analyze page to download data that is relevant for them and their specific transport mode.
Extreme heat affects all modes of transportation and can result in the rutting and bleeding of roads, the warping of railway tracks, safety concerns for marine shipping, and weight restrictions for airplanes.1,2,3 In response to concerns about these climate impacts, transportation authorities throughout Canada are investing in temperature-smart decision-support tools and protocols to inform investments in transportation planning, construction, operations, and maintenance.
For example, Manitoba Infrastructure requires that bridges and large culverts are constructed of materials that can withstand an 80°C temperature range (-40°C to +40°C).3 Similarly, the Ontario Ministry of Transportation uses the Superpave system to identify appropriate heat- and rutting-resistant asphalt mixes for provincial highways and for some municipalities.3, 4
These guidance processes are a step forward for climate-smart engineering standards. However, it should be noted that they rely on historical climate data. As the trend for most of Canada is towards higher maximum temperatures (Figure 1), it will be necessary to account for projected future temperature change in transportation infrastructure design.
It is not only transportation infrastructure that will continue to be affected by extreme temperature, but also transportation services and operations. For transit authorities, extreme heat or cold can impact worker health and productivity at construction sites, and busses without air conditioning can have negative impacts on customer comfort and satisfaction.5 In the aviation industry, extreme cold can cause delays, while extreme heat can necessitate weight restrictions on some airplanes.6 Importantly, the temperature threshold that results in airplane weight restrictions will vary based on the location of the airport, the size of the aircraft, and the length of a runway.6
To help address different transport sector needs in different locations, the Analyze page on ClimateData.ca allows users to specify relevant thresholds for custom data downloads, for any location in Canada. Analysis of extreme temperatures may otherwise be explored with a number of parameters on the Variable page of ClimateData.ca, including hottest day, maximum temperature, and days with a maximum temperature at multiple thresholds.
During periods of thaw, moisture from melting snow and ice is able to seep into cracks in infrastructure. When this moisture freezes and expands during freezing periods, infrastructure weakens and deteriorates.1,3
Greater variability in temperatures can therefore contribute to rapid deterioration of roads, and also of bridges, runways, taxiways, and railways.3 Reductions in the strength and in the stability of roadway infrastructure in turn increases the maintenance, renewal, and replacement costs.3 In northern Canada, these freeze-thaw cycles can perpetuate permafrost degradation, which has significant implications for northern transportation infrastructure.3 The integrity of railroad track is likewise reduced by rapid temperature cycling.5 Additionally, there are safety implications of freeze-thaw cycles as roads, sidewalks, and transit platforms may become slippery during these events and more uneven or unstable over time, therefore presenting increased slipping and tripping risks for users and workers.5
Throughout much of Canada, freeze-thaw cycles are expected to become more frequent in winter over the short-term, but freeze-thaw frequency may decline over the long-term as average winter temperatures rise (Figure 2).3,7 While the frequency of freeze-thaw cycles is still increasing, the potential for unsafe transportation conditions, rapid infrastructure deterioration, and maintenance costs will all rise as well.
Freeze-thaw cycles are commonly calculated as the number of days when the air temperature fluctuates between freezing and non-freezing temperatures (i.e. when the daily maximum temperatures are greater than 0°C and the daily minimum temperatures are less than or equal to -1°C). For some applications, climate data users might be interested in different definitions of freeze-thaw cycles. For example, some users may be interested in the frequency of days for which there is more extreme freeze-thaw cycling (i.e. the daily maximum temperatures are greater than 2°C and the daily minimum temperatures are less than or equal to -5°C). These custom data extractions for freeze-thaw cycles can be defined and downloaded by users on the Analyze page.
Transportation authorities across Canada are grappling with the changing frequency and intensity of precipitation events. From washed out highways in BC, to flooded commuter rail tracks in Toronto, extreme precipitation events are impacting the transportation sector across Canada.3,8 Extreme precipitation events lead to a myriad of other risks in the transportation sector: vehicle collisions, construction delays, and reduced commuter comfort, for example.5,9,10 As total precipitation levels increase, or as the severity and frequency of extreme precipitation events increase, the climatic impacts on transportation infrastructure are forecast to increase as well.
Transportation authorities are familiar with designing their infrastructure and operations with weather and current climate conditions in mind; but a rapidly changing climate is a new challenge. In fact, like many road authorities in Canada, the Ontario Ministry of Transportation (MTO) had focused on observed climate data to inform their selection of culvert sizes based on historical precipitation intensity-duration-frequency (IDF) curves.3,11 However, in response to projected changes in precipitation due to climate change, new initiatives have emerged to develop IDF curve projections. The MTO now selects culvert sizes based on future projected rainfall to allow adequate future capacity for extreme precipitation events.11 The same kind of reflection and work has been done in Quebec with the Ministry of Transport, academics, and several collaborators.
In another example, Canadian engineers had already begun to notice that our infrastructure is vulnerable to increasing damage from extreme precipitation. Engineers Canada partnered with Natural Resources Canada and several other collaborators to create a protocol to assess the risks to public infrastructure: PIEVC (see our case study here). After some initial testing, the PIEVC Protocol was used by the BC Ministry of Transportation and Infrastructure to assess the risks created on the Coquihalla Highway by extreme precipitation.8 It was found that heavy rain and snow events, among other things, were already creating challenging, even unsafe conditions on the Coquihalla Highway (located in a mountainous, coastal region of BC).8
In some instances, decision makers require information about precipitation projections for specific situations. ClimateData.ca currently offers a range of precipitation datasets, including: total precipitation, maximum 1-day total precipitation, and wet days with more than 1, 10, or 20 mm of precipitation.
Further, some users may be interested in the frequency of days for which there is more extreme precipitation (e.g. the number of days with maximum precipitation greater than 27 mm). These custom data extractions for projected precipitation can be defined and downloaded by users on our Analyze page.
Further development of the website and sector-specific modules will take into account user feedback. Please use the Feedback section to ask questions, provide comments and requests, or to submit examples of climate data use and/or adaptation in your area of expertise.