Risk Impact Analysis of Traffic Volume and Heavy Goods Vehicles in a Bi-directional Road Tunnel

摘要

A quantitative risk analysis regarding hourly traffic volume (VHP) and percentage of heavy goods vehicles (HGVs) in order to assess their impact on the risk level of a directional road tunnel was carried out. The results in term of social risk, as F/N curves, show that the risk level for certain combinations of VHP and percentage of HGVs is beyond the chosen safety limit (threshold of intolerable risk). As a result, safety measures in order to reduce the risk level must be taken. In this respect, the Tunnel Management Agency (TMA) can permit that HGVs pass through the tunnel only during night or during day along an alternative route that, forming a by-pass for the tunnel investigated, runs completely in open air. The paper also proposes risk charts that are useful for quickly assisting the TMA in making decisions on the most appropriate traffic control strategies.