Solving Minimum Cost Multi-Commodity Network Flow Problem Using Lexicographic Goal Programming Approach

In an urban transport system, a dysfunction often occurred as demand for transportation infrastructure exceeds available supply. The result includes traffic congestion, higher travel time and cost, higher emission of harmful gases and general reduction in quality of life. In this research, an attempt was made to minimize travel time on three urban road segments using Lexicographic Goal Programming. The positive and negative deviations from the goals were minimized. A minimum cost multi-commodity network flow problem with multiple objectives was successfully modelled using LINDO 6.1. The modelling technique provided a solution that effectively minimized travel time by 50%

Spatial Analysis of Accident Spots Using Weighted Severity Index (WSI) and Density-Based Clustering Algorithm

This study is based on evaluation of various factors that cause road accidents in Lagos Metropolis. Fourteen (14) factors/drivers were identified which tend to influence an occurrence of accident on Lagos roads. In order to study the pattern of accidents in the Metropolis, several different spatial and non-spatial datasets were collected, processed and analysed. Weighted Severity Index (WSI) was created based on these factors/drivers. Also, Density-based Clustering for Traffic Accident Risk (DBCTAR) was carried out to assist in ascertaining the distribution of Black Spots Severity (BSS). Results obtained include: shortestpath analysis, service area analysis, accident spot severity and vulnerability level across the Metropolis based on the Weighted Severity Index (WSI). The study reveals that, accidents are not always caused as a result of bad roads but by the smoothness of roads such as expressway with accident spots distance band of 300m-500m and 3.6% of the accidents is as a result of pedestrians avoiding the use of pedestrian bridges/aid even when they are available.Key Words: Accident Spots, Weighted Severity Index (WSI), Vulnerability, Pedestrians, Transportation

Creation of a Cell-Based Digital Cadastral Mapping System (Digital Cadastre): A Case Study of Goshen Beach Estate, Lekki Peninsula, Victoria Island

The analogue ways of land administration over the years in developing countries have brought retrogression to land development and its sustainability as a limited natural resource. The use of pencil and papers in land management is outdated and has reduced efficiency. Fast delivery of land related products from government authorities and the private sector takes weeks or months. The need for transformation from analogue approach (traditional cadastre) into the digital technology era (digital cadastre) in order to derive the seemingly unlimited benefits is pertinent. Digital cadastre enhances land transaction activities to be conducted in a business manner. Similarly, land subdivision or boundary redefinition, land registration and land marketing are achieved with better accuracy. This paper discusses the need to introduce a national Cell-Based Digital Cadastral Mapping System model (DCMS) that spans from the federal level down to the states, local governments and the private enterprises such as estate surveying firms. That is, from geodetic accuracy to tertiary (micro) accuracy in order to achieve a seamless nationwide digital cadastre coverage. At the micro level of creating DCMS, Goshen Beach Estate in Lekki Peninsula was used as a case study. The use of Unique Parcel Identifier (UPI) and Spatial Indexing were discussed. Quasi-Land analysis was carried out. From this study, it was discovered that productivity and delivery of land information are enhanced; opportunity of multiple users guides against data and resources duplication; and legal, technical (organizational and technological) and financial issues are better tracked and tackled using DCMS.Keywords: Cadastral, Geographic Information Systems (GIS), Multipurpose Cadastre, Parcel, Topographic Map