Norwegian Public Roads Administration's Climate and Transport R&D Project
Beginning in 2007, the Norwegian Public Roads Administration (NPRA) conducted a major research and development project to evaluate the impacts of climate change on Norwegian roads and recommend adaptation measures to be incorporated into road design, construction, operation, and maintenance and help ensure safety and accessibility of roads in a changing climate. The project, entitled “Climate and Transport,” has resulted in revised guidelines and specifications, to better plan and design for increasing risk related to flooding and sea-level rise. In addition to updating current manuals, new guidelines were also developed to protect roads from rockslides, snow avalanches, and slush avalanches. The final report on the project was published in 2013.
To assess vulnerabilities to the road network and develop recommendations, NPRA used findings from the report “Climate in Norway 2100,” which was developed by the Norwegian Climate Center and provided the basis for adaptation work in all sectors. The report modeled annual and seasonal projections for six different temperature and thirteen different precipitation regions throughout Norway. Climate change is projected to result in more precipitation in most regions and seasons, as well as more heavy rain events throughout Norway. From this, Norway is likely to experience larger and more frequent flooding caused by rainfall, while declining winter snowfall and a shorter snow season will likely result in fewer springtime floods caused by melted snow. More days with heavy precipitation are also expected to increase risk of landslides and wet/slush avalanches in hilly areas. Temperature is expected to increase most prominently in the winter and least in the summer, with Norway’s northernmost county experiencing the most average annual warming, potentially 3 to 5.4 degrees Celsius by 2100.
As a result of the Climate and Transport research project, NPRA developed specific adaptation measures to employ at different timescales and stages of decision-making. For new roads, NPRA developed the following adaptation measures to improve planning, design, and construction:
- Guidelines now require that climate change impacts like landslides and flooding be considered in siting roads, particularly where they cross waterways, and these hazards should be avoided or minimized through siting whenever possible.
- New roads must be elevated in accordance with the 200-year flood levels, with an additional safety margin added based on factors such as network redundancy and quality of data. Design must also consider the impacts of sea-level rise and increasing storm surge. New bridges must also be elevated and designed to resist erosion based on the 200-year flood levels and loads. NPRA also recommends analyzing risk to new bridges from 1000-year floods to avoid loss of life and other catastrophic consequences.
- New road projects will plan for stormwater management, and are encouraged to utilize more expansive drainage solutions such as alternative floodways, retention ponds, and protective ditches.
- Culverts and drainage pipes will be designed with a “climate safety factor,” greater than 1 and determined based on best available data, to calculate the necessary capacity.
For the existing road network, NPRA has identified the following needs and adaptation measures to better operate, maintain, and mange infrastructure in light of climate change:
- Inventory vulnerable assets to help set priorities for adapting assets through maintenance and operations. Conduct more detailed analysis of assets identified as vulnerable. NPRA has proposed guidelines for this inventory and analysis.
- Update risk-analysis procedures to aid operations and maintenance teams, to better develop contingency plans for weather events, and to better identify bridges, culverts, and road sections as vulnerable assets.
- Revise design rules to include better calculations for water flow and capacity.
- Incorporate climate change into models for landslide risks and into decision-making to prioritize road protection measures. NPRA has developed new guidelines for protecting against rockslides (most common), snow avalanches, and “wet” or “slush” avalanches.
- Model future deterioration and costs of maintenance, for both asphalt and gravel roads.
In addition to design and operational changes for new and existing roads, NPRA also recommended the use of new decision-making systems and tools to improve emergency preparedness for natural hazards:
- A “stepwise” system for preparedness against avalanches, floods, and other hazards affected by climate change. The system would include three alert levels corresponding with the likelihood of a natural hazard and level of preparedness required, to indicate when operational measures should be taken proactively to avoid damage to infrastructure.
- The web tool Xgeo monitoring of current weather data compared to threshold levels for floods, landslides, and avalanches, to help assess risk in real time.
- An alert system to disseminate data about hazardous events.
- An improved template for communication between NPRA and operations contractors to provide contractors information about a particular road stretch in question and previous repairs and statistics related to flooding and landslides in the area.
The Norwegian Public Roads Administration is responsible for planning, building, operating and maintaining Norway’s national and county roads. NPRA has included climate change in preliminary studies informing its long-term planning process for the three most recent versions of the country’s National Transport Plan. To complete the Climate and Transport project, NPRA worked closely with the Norwegian National Rail Administration and other partners such as the Norwegian Meteorological Institute.
This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on March 30, 2016.
Publication Date: May 2013
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