Road Tunnels Manual

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The World Road Association (PIARC) is a governmental organisation that aims at fostering and facilitating global discussion and knowledge sharing on roads and road transport. This is delivered by Technical Committees that it creates and coordinates.

The need to bring together the experiences gained in the field of the tunnel operations goes back several decades. This is why, in 1957, PIARC created the "Road Tunnel Committee" to address a range of aspects concerned in the use of road tunnels, such as geometry, equipment and its maintenance, operation, safety and environment. Since that date, this committee has produced technical recommendations in these various domains, in particular in the form of technical reports and of articles published in the Routes/Roads magazine. These recommendations are substantially followed worldwide and they are even often used as the basis for contractual specifications in many countries.

In 2007, it was considered useful to group, to synthesize and to update this large quantity of information disseminated in these various reports and articles. Such a synthesis document was realized in the form of an electronic encyclopaedia.

This electronic encyclopaedia, called "Road Tunnels Manual", comprises two principal parts. The part “Transverse aspects” contains 5 chapters that consider general aspects of road tunnels. The part “Operational and Safety Requirements” of the Manual contains 4 chapters and addresses particular elements of tunnels taking these requirements into consideration. The Manual ends with a Glossary which describes 200 terms and definitions translated into twenty languages.

In order to give a broad audience to this PIARC Manual, it is available in 10 languages. The English, French and Spanish versions are original versions validated by the technical committee. The Arabic, Chinese, Korean, Italian, Japanese, Portuguese and Czech versions are translations of these original versions.

We hope that this Manual will constitute a useful and enjoyable reference work for all those who are concerned with road tunnels. We hope that this Manual can meet their needs and we wish to improve this Manual with your comments and suggestions so that it becomes for all a valuable tool which helps to support the effective and safe transport of goods and people in road tunnels.

We invite you to begin by reading the following paragraph, "2. If it is your first visit !", to acquaint yourself with various features developed to return make this Manual user-friendlier and to help you to find more easily the information which you are looking for.

Enjoy your reading!


This site arranges several features which will allow you to navigate there more easily.
Choice of the language : English, French and Spanish are three official versions of this Manual. It is also available in Arabic, Chinese, Korean, Italian, Japanese, Portuguese and Czech: these versions are translations of the official versions. To choose one of these languages, you just have to click on the name of the wished language in the right upper side of the screen: you will automatically be redirected towards the chosen linguistic version, on the same page as the one on which you are.
Search tool : if you type a term in the window situated next to the menu "Tools" and if you click then on the magnifying glass, all the locations where this term exists will automatically be listed. You will just have then to click on the choosen title to be automatically redirected towards this page. You can refine your search by clicking on the small white triangle which appears next to the search window (Typology, Chapters of the Manual, Date of publication).
Printing : if you click on the red icon PDF then on "Current page", you will reach the printable PDF file of the page. If you are on a front page of a chapter or a book, you can also click on "Entire chapter" and reach the printable pdf file of the whole chapter or book.
Return at the top of page : click the white arrow in the right edge of the page.
Acronyms : acronyms are underlined by a blue intermittent line. If you maintain your pointer above, the meaning of this acronym will appear in a pop up.
Subscribe : if you wish to be warned of every modification of  the Manual, you just have to click on "Subscribe" in the window "Stay informed!" at the top of the homepage or at the bottom of all other pages.
An opinion or a comment : if you wish to contact the persons in charge of the Manual for an opinion or a comment, you just have to click on "Click here" in the window situated at the bottom of each page and then to complete the form.
Contact PIARC : if you wish to send a message to the PIARC General Secretary about the Manual in general or about the technical committee "Road Tunnel Operations" and its products, you just have to click on "Contact PIARC" at the very bottom of any page then to complete the form.


Copyright by the World Road Association. All rights reserved. Any reproduction even partial is forbidden without written authorization granted by the World Road Association.

World Road Association (PIARC)
Tour Pascal B - 19th floor
5, Place des Degrés
F-92055 La Défense cedex

Tél + 33 (1) 47 96 81 21
Fax + 33 (1) 49 00 02 02


  • The official versions of the Manual are the English and the French versions. The versions in other languages are translations of the official versions but these translations are not officially validated by PIARC.
  • Although sections of reports are selectively referred to in this electronic resource, the actual meaning must be determined in the context of the original report - not the context of the electronically extracted web page.
  • Where there is a conflict between the web site and the full report - the full report takes priority
  • Publication on the web site is not a contemporary endorsement of the currency of the material and views contained in the earlier report.
  • Specific inclusion in the web site does not add priority or authority to the original report.
  • Where there is a requirement to comply with PIARC requirements as at a certain date, that date is determined by the date of first publication - not subsequent publication on the web site.
  • Where a reference is made to another organisation or a web site hosting documents from such an organisation, the link does not constitute an endorsement of the specific recommendations contained at that link at the time it was published, or at any future time, unless and strictly limited to, the specific recommendation cited with approval in the tunnel handbook.
  • The World Road Association does not accept any liability whatsoever, neither in contract nor in tort, for usage of this Manual. Any risk relating to interpretation and usage remains entirely with the readers. 


This Manual was designed to be a "live" document in order to be able to follow the frequent technological developments that are adopted from the design to the operation of the tunnels, and to be able to easily integrate the new reports that will be produced by the committee during following cycles. In this first version (2008-2011), the committee members have primarily endeavoured to define the structure of the Manual and to integrate into it, by means of new text or hyperlinks, the most relevant documents that already exist. Later, the old texts will be up-dated and up-graded as necessary and on this occasion the integration of their content within the Manual will be examined when appropriate.

All the updates are listed here below, starting from the initial version v 1.0 of the Manual in English from 25 September 2011.


a) v 1.0 of 25th September 2011

Are still missing in the Glossary of this version, the terms and definition of the PIARC Road Tunnel Operations dictionary translated in Czech, Chinese, Danish, Dutch, Farsi, Finnish, German, Hungarian, Japanese, Norwegian, Portuguese and Swedish. They will be added when available.

b) v 1.1 of 27th October 2015

The French, English and Spanish versions of the Manual were moved towards a new site with new functions. The content of the Manual pages remained identical except:
  1. Homepage: the first 2 paragraphs have been added and the PIARC address updated.
  2. Pages of the main Menu: pages "Introduction", "Transverse Aspects" and "Operational and Safety Requirements" have been added.
  3. The former page "Introduction" has a new title: "Road Tunnels Manual"
  4. The page "Glossary" appears in the menu "Tools". It has been updated to take into account the integration of all the former PIARC dictionaries in a single one. The Excel files resuming all the terms and definitions were also updated with the translations in 19 languages available today (Portuguese is still missing).
  5. Two new pages were created in the menu "Tools":
         - "Acronyms"
         - "Useful Links"
  6. Chapter 1 "Strategic issues" has been completed by section 1.7 "Complex underground road networks" with its case studies.
  7. The readability of some figures and tables was improved.
  8. PDFs of pages are automatically generated and their layout is slightly modified.
Reference sources

No reference sources found.