According to the standard, road tunnels like this one had to be designed with fire safety features such as:
Let’s walk through a scenario: You are designing a 1.5 km bi-directional road tunnel. According to the standard, road tunnels like this
Jump to Table 5.4.3.1.1. Select a design fire of 50 MW (bus fire). Apply the critical velocity formula from Chapter 8. Use the PDF’s search function to find “Kennedy” – you’ll locate the exact equation: (V_crit = 0.61 \times (Q / \rho c_p T_f A)^1/3) … adjusted for tunnel slope. According to the standard