This updated, second edition unveils the mystery of the tunnel fires, covering most of the issues in fire safety engineering in tunnels, clearly describes the phenomena related to tunnel fire safety, presents state-of-the-art research, and gives detailed solutions to these major issues.  The book retains its chapters on fuel and ventilation control, combustion products, gas temperatures, heat fluxes, smoke stratification, visibility, tenability, design fire curves, heat release, fire suppression and detection, CFD modelling, and scaling techniques allowing readers to create their own fire safety plans for tunnels. It gives detailed solutions to the major issues in fire safety engineering in tunnels and provides example calculations. A new chapter on Alternative Fuel Vehicle (AFV) safety has been introduced as well as updated information related to AFVs in respective chapters.