Evaluating the Role of Urban Spatial Structure in Functionality of Streets

This paper is intended to determine whether there is a meaningful relationship between urban spatial structure and functionality of streets. Urban spatial structure refers to spatial configuration and arrangement of streets in an urban transportation network. Also، in this context، functionality of a street defines if the street is an arterial or local path. In order to evaluate the spatial structural properties of streets in an urban transportation network، this paper applies an indicator called “Shortest Path Frequency” (SPF). This indicator determines the frequency in which a given street participates in possible shortest paths throughout the network. Higher SPF indicates that the street is more structurally important. Moreover، in order to achieve the mentioned goal، the SPF indicator was adopted to assess the structural importance of streets in a case study network. Then، the assessed importance of each street is compared to its functionality in real network. The functionality of streets was categorized in four level including: main arterial، secondary arterial، main streets and local streets. The comparison between calculated and observed importance of streets was achieved by using a statistical test. The test revealed that there is restrict meaningful relationship between structural importance level of streets and functionality of streets. In other words، the streets which were identified as structurally important also are identified in the category of main or secondary arterials in real world. As a result، this procedure can help urban designers to predict structurally important streets in a network and provide required plans such as particular land-use policy or specific design to avoid from congestion in such streets.