Evaluation and Classification of Al-Najaf Road Urban Network

Abstract

One of the basic parts that cities depend on for movement and mobility is a road network. Therefore, improving and developing is network directly or indirectly affects various social, cultural, and economic activities. Al-Najaf is a city in Iraq that is currently undergoing development, but is facing challenges with traffic congestion in multiple areas of its street network. Regular diagnosis of the causes, locations, and severity of traffic congestions is crucial for two primary reasons. Firstly, it enables the classification of roads based on the gradual increase in vehicular traffic over time. Secondly, it facilitates the proposal of traffic engineering solutions that are tailored to the existing road networks. This study aims to assess the overall performance of the primary urban streets within the street network of Najaf city during morning and evening peak hours. The collection of field data involved the use of a video camera for the purpose of determining traffic volume, as well as conducting traffic surveys that entailed measurements of lane count and length. Additionally, a speed gun was utilized to ascertain the speed of free flow. The evaluation procedures from the Highway Capacity Manual (HCM) are utilized to evaluate the operational efficiency of designated urban roads. As per the research findings, certain roads that exhibit free flow speed characteristics akin to highways during the early morning hours have been categorized as Classes I and II instead. The findings suggest that the percentages of urban street categories, including principal and minor arterials, collectors, and local roads, do not conform to the established sustainable standards outlined in the sustainable road hierarchy.