Research results

"The Road Tunnel Maintenance Handbook (Facilities Edition)" published

1. Introduction

  In 1993, the "Road Tunnel Maintenance Handbook" was published, covering road tunnel maintenance and management, and this came to be used as a helpful source in practical work. In the aftermath with the Sasago Tunnel ceiling collapse of 2012 as a turning point, Guidelines for Periodical Inspection of Road Tunnels1), 2) were issued in June 2014, and the "Road Tunnel Maintenance Handbook (Civil and Structure Edition)"3) was published in June 2015. The handbook of tunnel facilities edition4) (hereinafter, "this Handbook") was published in November 2016 as a follow-up to the Civil and Structure Edition, featuring expanded contents based on the latest knowledge of maintenance and management covering facilities that are provided in road tunnels. With this Handbook, you will be able to gain a comprehensive understanding of matters relating to the maintenance and management of facilities in tunnels. Here we introduce the main revised contents.

2. Detailed explanation of inspection technique

  Tunnel facilities for ventilation, lighting and emergency are installed in road tunnels to ensure safe, comfortable and smooth traffic. This Handbook describes contents to help with inspection-based understanding of how abnormal installation, etc. affects facility functions and users, as well as supporting appropriate measures to be taken. In particular, in covering the causes of failure in facilities, there are photographs, etc. of abnormal conditions resulting from wear of equipment and parts as well as external factors, together with detailed explanations of these abnormalities. In addition, this Handbook introduces the latest points concerning road-related machines and telecommunications equipment, etc., together with descriptions regarding the relevance of the types of inspections shown in this Handbook, and has been prepared so as to make all inspection-related matters easy to understand.


Vol. 1  General
  Chapter 1  General rules
Vol. 2  Tunnel facilities
  Chapter 1  Outline
  Chapter 2  Inspection
  Chapter 3  Diagnosis
  Chapter 4  Measures
  Chapter 5  Records
  Chapter 6  Ventilation facilities
  Chapter 7  Lighting facilities
  Chapter 8  Emergency facilities
  Chapter 9  Power distributors and stand-by generators, etc.
  Chapter 10  Remote surveillance control facilities
  Chapter 11  Other facilities
  Chapter 12  Cleaning
Attached documents
  1. Examples of facility inspection check-sheets
  2. Laws and standards for maintenance and management of road tunnels
Handbook contents

Road Tunnel Maintenance Handbook (Facilities Edition)
(Japan Road Association, November 2016)

3. Detailed explanation of points to note at time of inspection

  Facilities installed in road tunnels are categorized into "facilities", "equipment", "apparatus", "machinery" and "parts", with photographs and outline descriptions of apparatus and equipment, etc. in order to deepen understanding in daily maintenance and management as well as inspection. Also, since each facility has various purposes, functions and characteristics, detailed descriptions have also been provided of items to be kept in mind during inspection.

4. Conclusion

  In addition to the above-mentioned items, this Handbook also contains: inspection checklists with examples of inspection judgment methods and criteria relating to the recording of inspection results, views regarding surveillance measures, and details of the latest technologies for maintenance of tunnel facilities.

  This Handbook is expected to be helpful in road tunnel maintenance and management and ensuring safety going forwards.


  1) MLIT Road Bureau: Guideline for Periodical Inspection of Road Tunnels, June 2014

  2) MLIT Road Bureau, National Highway and Risk Management Division: Guideline for Periodical Inspection of Road Tunnels, June 2014

  3) Japan Road Association: Road Tunnel Maintenance Handbook (Civil and Structure Edition), June 2015

  4) Japan Road Association: Road Tunnel Maintenance Handbook (Facilities Edition), November 2016

(Contact: Tunnel Research Team, Road Technology Research Group)

Development of a Machine for Maintaining Winter Sidewalk Surfaces

Photo 1 A snow- and ice-covered sidewalk

Photo 1 A snow- and ice-covered

Photo 2 The developed machine attached to a small snow removal vehicle

Photo 2 The developed machine attached
to a small snow removal vehicle

Photo 3 Before treatment (left) and after treatment (right)

Photo 3 Before treatment (left)
and after treatment (right)

Fig. 1 Coefficient of static friction (measured by American Slip Meter)

Fig. 1 Coefficient of static friction
(measured by American Slip Meter)

1. Purpose of development

  On winter sidewalks in regions with severe winter conditions such as Hokkaido, hard, uneven snow- and ice-covered surfaces often form from repeated treading by pedestrians and repeated freezing and thawing from changes in the air temperature (Photo 1). Because of these sidewalk surface conditions, there have been many pedestrian slip-and-fall accidents. The main anti-skidding measure has been the spreading of fine crushed stone. However, fine crushed stone often loses its effectiveness in a short period of time under certain weather conditions. Additionally, the application of fine crushed stone necessitates cleanup in early spring.

  As an anti-skidding technique to replace the spreading of fine crushed stone, we developed a machine for treating the surface of snow- and ice-covered sidewalks.

2. Outline of the machine

  The developed machine was designed to attach to the small snow removal vehicle that is generally used for sidewalks and to treat the snow- and ice-covered sidewalk surface (Photo 2).

  This machine breaks the hard snow and ice by using a rotating drum whose surface is installed with crushing blades made by cutting the tips of round steel bars at an angle. The drum is pressed against the sidewalk by the machine's weight and is rotated by the propelling force of the small snow removal vehicle. Ice and hard snow fragments of about 5cm in length are generated when this machine operates. The machine removes these fragments to both sides of the walking zone by using the blade at the back of the machine.

  The machine is distinguished by not needing an independent power source to rotate the drum.

  The machine is capable of determining the breaking depth of snow and ice, because use of this machine on a layer of snow and ice of 2cm or thinner may damage the pavement surface.

3. Work effectiveness of the machine

  The results of work using the machine are shown in Photo 3 and Fig. 1. The coefficient of static friction was greatly increased by the treatment. The results of the treatment of the icy surface with many bumps and indentations verified that the machine breaks more ice at the bumps than elsewhere and makes the sidewalk surface level and easy to walk on.

  This treatment can be expected to have lasting effectiveness, even with some changes in the weather, because the machine breaks the slippery surface of the snow- and ice-covered sidewalk.

(Contact: Machinery Technology Research Team, Civil Engineering Research Institute for Cold Region)