Journal of Korean Society of Transportation ISSN:1229-1366(Print) 2234-4217(Online) 대한교통학회지

Previous studies have introduced various traffic operation and management techniques in strategic schemes against sudden traffic incidents in highway networks. However, no specific guideline has been available to determine the spatial boundaries of such techniques for implementation in practice. This study proposes a layout to determine a spatial boundary of such techniques based on historical data in the Seoul metropolitan area. The data include (1) travel speeds (automatically stored every five minutes over a year) of all links in the city, and (2) historical traffic accident records (day, time, location, the number of lanes closed, and so on). Through the combinatory analysis of these data with a geographical information system, it was found that there were general tendencies after the occurrence of incidence – how wide and how long the effects of incidents last. It classified the properties of accidents based on their time duration (less than 30 min, 30-60 min, and higher than 60 mins) and the space left available (the number of lanes available is one, two, and more than three). It also defined the levels of spatial boundary, numbered from one to five, which represents the number of upstream links from the one in that an incident occurs. This study found that the longer the incident duration, the wider the effect of the traffic incident. When the number of available lanes is one, the impact of the traffic accident is greater. In the case of two or more available lanes, there was a tendency that the spatial boundary was identical while the travel speed changes were affected by incident types.