Road Tunnel ventilation Systems: Technical Paper TP04

Research output: Book/ReportBookpeer-review


Road tunnels are an important part of transport infrastructure. Originally, they were built to improve traffic and transport conditions in mountainous regions; however, they are now often built in urban areas to reduce traffic congestion and improve local air quality. As road tunnels create an enclosed space around vehicles, ventilation is required to dilute vehicle emissions to provide a safe environment for tunnel users, and to support smoke dispersion/extraction in cases of incidents.
Basic concepts of ventilation have not changed over the last few decades. Traditionally, due to fresh air supply requirements, longitudinal ventilation was limited to shorter tunnels with transverse ventilation used in long tunnels. Improved vehicle emission technology and the construction of twin tube tunnels operated with unidirectional traffic now safely enables the use of longitudinal ventilation systems also for long and heavily trafficked tunnels. All long road tunnels built in Australia over the last 25 years have been designed with
longitudinal ventilation systems.
In urban areas, complex tunnel systems with multiple slip roads to the surface and interconnections with other road tunnels are a popular means to improve the flow of inner-city traffic. These tunnels require individual project based approaches to ventilation as well as ventilation control, and different or combined ventilation systems might be employed within the same tunnel network.
Tunnels in urban areas pose an increased risk of elevated pollution levels in the portal regions and may require management of tunnel air. Internationally, many longer tunnel systems in urban areas use stack dispersion only during peak traffic hours, while during the remaining time, tunnel air is released via the portals.
Original languageEnglish
Place of PublicationAustralia
PublisherAdvisory Committee on Tunnel Air Quality, New South Wales Government
Commissioning bodyAdvisory Committee on Tunnel Air Quality
Number of pages24
VolumeTP 04
Publication statusPublished - 3 Dec 2019


  • Tunnel ventilation

ASJC Scopus subject areas

  • Engineering(all)
  • Mechanical Engineering

Fields of Expertise

  • Mobility & Production

Treatment code (Nähere Zuordnung)

  • Review

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