Street Network Reliability Evaluation Following the Chi-chi Earthquake

Abstract

Street closure following an earthquake makes life-saving and rescue work more difficult, especially in congested urban areas. After the great Chi-chi earthquake, recovery and reconstruction work became necessary. In particular, we have to investigate the street network damages and other effects. Considering the road improvement plan, not only malfunction recovery but also a comprehensive evaluation should be considered in future urban planning. The reliable street network against earthquakes is the central concern of this survey.

This study attempts to implement a case study survey of damaged areas, and analyze the effecting factors on street closure. We also try to evaluate the road function against earthquake integrated with the street-damaged characteristics. Using a discriminant model of street closure, some design guidelines for future transportation planning decisions are proposed.

Nan-tou City network has 365 links and 66.6% of them are less than 6 meters in width. Ton-shi Town network has 248 links and 35% of them are less than 6 meters in width. The same definition of street closure (impassable by vehicles) of ‘street width less than 4 meters’ was applied to these two case studies. This research considered several street network alternatives, the inaccessible nodes for all alternatives and analysis in order to determine a more reliable street network for increased safety. Results of both surveyed areas suggest that when we decrease the interval distance of the 8-M street, the percentage of the differences of inaccessible nodes will also decrease.

The Chi-chi earthquake did great harm in the disaster area. Fortunately we find the street damages of our surveying area were not too severe to maintain their functions in times of earthquake. However, it is still meaningful for a transport planner to evaluate the reliability of residential streets because the main target of planning a residential street network is to restrain through-traffic in this area to ensure safe and comfortable conditions for pedestrians while meeting residential access requirements.

Citation

Lung Lee, Y.-. and Yih Yeh, K.-. (2003), "Street Network Reliability Evaluation Following the Chi-chi Earthquake", Bell, M.G.H. and Iida, Y. (Ed.) The Network Reliability of Transport, Emerald Group Publishing Limited, Leeds, pp. 273-288. https://doi.org/10.1108/9781786359544-016