1.1 Introduction
Intersections are locations where complex and heavy maneuverings occur; thus, they must be properly designed and equipped to handle traffic for easy and safe turnings. Intersection plays an important role in the road network, where traffic flowing in different directions crosses each other. Traffic and geometric data for the selected intersection have been collected. And the result of this research shows high magnitude of degree of saturation, delay and queue length and low magnitude of capacity for the selected intersection in the city. Volume of pedestrians and Bajaj traffics are the main causes for this. The traffic intersection is one of such transportation/traffic infrastructures that pose challenges of lowered level of service occasioned by congestion and traffic sprawl especially in the urban centers.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Traffic congestion on urban roads results in tremendous economic loss, additional delay and user cost. Intersections play an important role in the road network, where traffic flows in different directions converge. Because of disturbance of pedestrians, mixed traffic and lost time for beginning and clearance etc., capacity or the maximum rate of flow at which persons or vehicles can reasonably expected to traverse an intersection is much lower than their approach links. Thus, intersections are usually the bottleneck of the network and are the greatest and immediate source of traffic accidents. Hence, level of service at intersection significantly affects the overall level of service of the road. The critical aspect of increasing capacity of any road lies in increasing capacity of the intersection.
Traffic signals, roundabouts, stop and yield controls are commonly used in several at grade junction in urban areas to maximize traffic efficiency and safety by separating conflicting traffic movements in time (Hemant et al., 2017). And Intersection performance measures used to evaluate the intersection performance (TRB, 2000) appropriately at these days based on different manuals. Capacity which is the maximum sustainable flow rate that can be achieved during a specified time period under a given (prevailing) road, traffic and control conditions and degree of Saturation or the ratio of arrival (demand) flow rate to capacity during a given flow period are relevant measure of performance of intersections.
Delay which is additional travel time experienced by a vehicle or pedestrian with reference to a base travel time is also one of the measure performances of intersections. Among others queue length is a more useful performance measure of intersections because it is relevant to the design of appropriate queuing space, e.g. for short lane design to avoid queue spillback into adjacent lanes, for phasing design to avoid blockage of upstream signals in paired intersection situations, and for signal coordination offset design to prevent interruption of platoons by downstream queue.
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Performance Assessment of Selected Intersection in Akure.
1.3 Statement of Problems
Investigation revealed that performance evaluation of intersection in Ethiopia is focused only on highly congested junction areas in Addis Ababa. And there is no sufficient study on the performance of intersections in other cities of the country to handle the problem of congestion, delay and accident in the intersection areas before they become congested. Most of the intersections in the major road ways of Ondo city are closely spaced with high traffic of pedestrians and motorized vehicle such as Tricycle, taxi, bus, truck etc. in the peak hours so that their performance is highly affected by it. In addition to this, growing vehicular and pedestrian traffic in the city may also reduce performance of the intersections more than ever in the near future.
1.4 Aim and Objectives of Study
The aim of the study is to assess the Performance of Selected Intersection in Akure, Nigeria. In achieving this aim, the following specific objectives were laid out as follows:
- To evaluate the performance such as; capacity, degree of saturation, delay, queue length, and level of service of roadway intersection in the area under study;
- To evaluate the performance of the selected intersection that is located around Akure in Ondo city; and
- To study the special effect of pedestrians and Vehicles in the performance of intersections.
- To give recommendation in designing as well as improving the performance of the intersection for the future in the city.
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:
- How can intersection design be improved the performance of the intersection for the future in the city?
- What is the performance of service of roadway intersection in the area under study?
- What is the performance of the selected intersection that is located around Akure in Ondo city?
- What is the special effect of pedestrians and Vehicles in the performance of intersections?
1.6 Research Hypothesis
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
Hypothesis One
- H0: There is no significant effect of pedestrians and Vehicles in the performance of intersections in Akure, Nigeria
- H1: There is a significant effect of pedestrians and Vehicles in the performance of intersections in Akure, Nigeria
1.7 Significance of Study
The research will be important for designing and improving the performance of intersections in the future for the city. And also it will be important for design, operations and planning purposes in traffic management in the city as well as for other cities which have similar traffic and topographic conditions in Nigeria in general. The findings obtained from the study would be helpful to gain information and knowledge about the analysis and design of intersections.
This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.8 Scope of Study
The scope of the research is focused on the Performance Assessment of Selected Intersection in Akure, Nigeria.
1.9 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).
1.10 Definition of Terms
Intersection: Intersection is an area shared by two or more roads.
