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Adaptation of French standards for design, maintenance and operation of transport infrastructures

Adaptation of French standards for design, maintenance and operation of transport infrastructures (2015)

At the request of the Ministry of Ecology, Sustainable Development and Energy (DGITM), the Cerema under supervision of the French Administration, completed in 2015 a systematic review of standards and guidelines on the design, maintenance and operation of transport infrastructures. The aim of this review is to adapt transport infrastructures and systems to future climate conditions and foster greater resilience to the effects of extreme weather events. The screening process is being followed by the actual revision and update of the standards, in order to cope with the foreseen changes in climate by 2100; the new standards will replace the existing ones for the design, maintenance and operation of transport infrastructure. The final purpose of the process is to make sure that transport infrastructure, with a long time span of service (sometimes of 100 years or more) can satisfactorily cope with the conditions imposed by future climate and extreme weather events.

Case Study Description

Challenges

Some significant changes in the French climate by 2100 were identified in the climate studies conducted in 2011 and 2012, in the framework of the preparation of the National Climate Change Adaptation Plan. Those with a potential impact on transport infrastructure include:

  • Temperature: increase in average temperature (+3,5 °C in one century under the "pessimist" scenario), decrease in the number of frozen days, and changes in daily temperature variations.
  • Rain: precipitation tends to decrease in spring and summer; reduction in the number of snowy and rainy days.
  • Water: surface water with increased flows in winter and more severe low flows in summer (these trends are likely to vary according to watersheds); annual average groundwater levels would tend to decrease, although seasonal fluctuations are still unclear.
  • Wind: high uncertainty on the expected changes, as there are many differences in the results provided by the models.
  • Sea level: projections are uncertain, especially at local level, but overall trend to a sea level rise; the hypothesis of sea level rise of 1 m by 2100 is retained for this revision process.
  • Wave regime: little documentation is available on its future evolution.
  • Extreme weather events: extremes would tend to increase in frequency and intensity; extreme rainfall associated with these events would decrease in frequency but increase in intensity. Results from modelling of extreme weather events like hurricanes or storms are still very uncertain.

These changes in climate pose specific challenges to transport infrastructure, which will be addressed through an update of the relevant standards. The update process is however challenging for a variety of reasons:

  • Difficulties to identify how changes in climate can influence the climate-related variables traditionally used in transport standards and guidelines.
  • High need of communication on the necessity to anticipate climate change impacts and to adapt infrastructures to long term changes.
  • Huge number of transport standards and guidelines; there is the need to establish a sound priority in their revision and to provide common guidance for it.
  • Need to establish synergies, with on-going regular technical updates of transport standards and guidelines, and climate projections.
Objectives

The main objectives of the systematic review of standards are:

  • Adapt technical requirements of transport infrastructure to expected changes in climate.
  • Provide an unbiased review and identification of revision needs and priorities.
  • Address transport infrastructure resilience in a comprehensive way, including design, maintenance and operations.
  • Update climate parameters and indicators commonly used in transport standards, to take account of potential changes in French climate.
Adaptation Options Implemented In This Case
Solutions

The review has been carried out by a technical working group set up by the DGITM involving experts of different transport infrastructures and systems: roads, bridges, earthworks, cableway, railway, aeronautic, waterway, maritime and port sectors. After summarizing major climate trends at short and long term, the working group screened existing French standards, in order to identify those that include references to key climate concepts (such as "temperature", "flood", "rain", "wind"...) that could change in future. The screening, based on databases and expert opinions, mostly focused on technical documents; some regulatory and normative documents have also been taken into consideration. The selected standards were subsequently classified into three groups, in accordance with the needs for revision from a climate change adaptation perspective: (1) those with no need for revision; (2) those in need of revision, and (3) those needing more precise information of the climatic variables and indicators involved for assessing their revision needs. For the third group of standards, the existing information is not sufficient to assess whether there is a need to adapt them to future changes in climate, and further studies will be needed in future. Some examples of standards in each category follow:

  • Standards with no need for revision: road traffic noise, road landscape design, road drainage guidelines, recommendations for structural design (limit states) in aquatic sites.
  • Standards needing revision: road pavement design, estimate of general actions for aquatic structures (snow, wind, etc.).
  • Standards needing further clarifications of the climate parameters: design and construction of new roads, maintenance of urban roads, draining road pavements, guidance on road embankments, principles to laying of long welded rails.

Some hundreds of technical standards (more than 800 only for roads) have been revised. For those needing a more precise understanding of climate parameters involved (category (3) above), the transport experts have provided a list of the precisions required. These refer to the timing (when certain climate changes are likely to happen) and areas affected, or to the precise effects of those changes on some of the parameters used for infrastructure design (frequency of occurrence, intensity, number of days above certain levels, etc.).

Whereas the revision of standards within category (2) is already being undertaken, the revision of standards under category (3) can only proceed once the necessary clarifications have been provided by climate and meteorological experts. The revised standards will be adopted following the general procedure, including the participation of all relevant stakeholders, and subsequently implemented.

Relevance

Case developed and implemented and partially funded as a CCA measure.

Additional Details

Stakeholder Participation

The review has been undertaken in coordination with the DGITM (Directorate General for Infrastructure, Transport and Sea) by the different technical services of the French government: CEREMA (Centre d’Études et d’Expertise sur les Risques, l’Environnement, la Mobilité et l’Aménagement), CETU (Centre d’Études Techniques des Tunnels), STAC (Service Technique de l’Aviation Civile), STRMTG (Service Technique des Remontées Mécaniques et des Transports Guidés), and from the various public transport managers: RFF and SNCF (rail), VNF (inland waterways), and from IFRECOR (Initiative Française pour les Récifs Coralliens). Experts and researchers will be mobilized to calculate climate projections and to adapt the standards. The working group is also currently involved in the AFNOR’s coordination group “Climate Change”.

Success and Limiting Factors

This action provides an innovative approach to transport infrastructure adaptation as it tries to undertake a homogeneous methodology to review standards to be applied (in a climate change adaptation perspective) to different transport modes and to different phases, as design, maintenance and operations. Other success factors are:

  • Partnership with climatic experts and meteorological services. Climate and meteorological expertise is crucial to define future climate conditions and to understand their consequences for the various elements of transport infrastructure. Efficient partnership is based on a fruitful dialogue, with climate experts understanding the information needs of transport infrastructure designers and managers, and transport specialists adapting their practices to the climate information actually available and its related uncertainty.
  • Mobilization of in-house technical knowledge within the national administration, overcoming technical fields.
  • Pragmatic approach, aiming at establishing clear priorities in the revision process, and to achieve quick results for the selected priorities.
  • Transparency, allowing all interested parties to get access to the information produced by the working group and to the recommendations made.

Limiting factors include:

  • Heterogeneity in the contents and approach of existing standards within the different transport modes.
  • A few standards databases. Difficulties to identify all standards with climate-related variables: an absolute necessity to consult a high number of transport experts to list and review the standards.
  • High specialization in technical expertise, making it difficult to undertake common approaches that cross the traditional borders among "knowledge communities".
  • Standards for design, maintenance and operation are based on specific values of climate-related variables, whereas climate projections are often given as ranges of values.
  • Adaptation to long term climate change is often considered as a non-priority issue.
Costs and Benefits

Information on detailed costs is not available; however, as the activities have been carried out by the technical services of the French government, the process has not required significant additional resources.

Main benefits are expected to be related to long-term savings in operating and maintenance costs of transport infrastructure. The new standards will replace the existing ones for the design, maintenance and operation of transport infrastructure. The final purpose of the process is to make sure that transport infrastructure, with a long time span of service (sometimes of 100 years or more), can satisfactorily cope with the conditions imposed by future climate and extreme weather events.

Legal Aspects

The main legal framework of this review is the French National Climate Change Adaptation Plan (2011), which includes a mandate to the Ministry of Ecology, Sustainable Development and Energy (Direction Générale des Infrastructures de Transports et de la Mer) to set up a working group on this action.

Implementation Time

The working group should continue to work until 2016 (second phase of Adaptation Plan), launching the drafting of some of the standards and deciding on the need for revision of category (3) standards, based on the clarifications of the experts.

Life Time

The revised standards will be applied to the construction of new infrastructure and the upgrading and maintenance of existing one, with design life spans of 25 to 100 years.

Reference Information

Contact

Marie Colin
CEREMA
110 rue de Paris - BP 214 - 77487 Provins Cedex
Tel.: +33 (0)1 60523261
E-mail: marie.colin@cerema.fr

André Leuxe
Ministry of Ecology, Sustainable Development and Energy (DGITM)
La Grande Arche, Paroi Sud, La Défense, 92044 Paris
Tel.: 33 (0)1 40811320
E-mail: andre.leuxe@developpement-durable.gouv.fr

Source
Centre d’Études et d’Expertise sur les Risques, l’Environnement, la Mobilité et l’Aménagement (CEREMA)

Keywords

Design, maintenance, operation, standards

Sectors

Transport

Climate impacts

Extreme Temperatures, Flooding, Ice and Snow, Sea Level Rise, Storms

Governance level

National

Geographic characterization

Europe

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