01152102

Component

Quantitative Risk Analysis (QRA) models have recently been proposed for assessing the societal risk expressed by a frequency / number of fatalities (F/N) curve of road tunnels. For a particular road tunnel, traffic volume and maximum percentage of vehicles carrying hazmat passing though the road tunnel are two key parameters influencing the societal risk. To evaluate impact of these key factors on the societal risk, this paper first presents a QRA model based procedure that employs the QRA model to generate F/N curves for all the possible combinations of these two factors. Some combinations of these two factors may result in F/N curves which do not meet a predetermined safety target. This paper thus proposes an excessive risk index of an F/N curve to quantify magnitude of the excessive risk. The two-factor impact analysis can be illustrated by a contour chart based on excessive risk. Finally, a road tunnel case study in Singapore is carried out. It has shown that the maximum tolerable traffic volume rate is 1400 vehs per hour per lane with a maximum acceptable proportion of hazmat transport not more than 2%. Further discussion also shows that higher traffic volume could be acceptable if certain effective operational procedures are taken to reduce the risk of transportation of hazmat.

01147878

10-3001

English

14p

2010

Transportation Research Board 89th Annual Meeting

DVD

Figures (5) ; Maps (1) ; References (26)

Case studies; Fatalities; Hazardous materials; Highway safety; Impact studies; Risk assessment; Traffic volume; Tunnels; Vehicular tunnels

Singapore

Highways; Operations and Traffic Management; Safety and Human Factors; I73: Traffic Control; I85: Safety Devices used in Transport Infrastructure

Transportation Research Board Annual Meeting 2010 Paper #10-3001

TRIS, TRB

Jan 25 2010 11:28AM