Efficiently identifying closed roads by integrating and indexing open data

Abstract

CAP messages are the standard ways for the government to broadcast emergency messages, which are represented in the XML format to meet the open data initiatives. However, such formats are hard for ordinary people to understand, and the current user interface in the official website has only limited functionality. In this research, we focus on the type of CAP messages indicating a closed road and study how to support more advanced querying facilities. Particularly, we allow users to issue a specific address or a particular period of time, and wish to return the closed-road events which satisfy the given constraints efficiently. To meet the above need, we integrate the CAP messages and another set of open data, i.e., the road mileage map, and construct the spatial index and the temporal index on them. The proposed approaches were implemented and extensive empirical studies were conducted by using real open data retrieved from the governmental website. Experimental results have shown their efficiency and good performance.