Introduction Once a transportation plan has been finalised and the demand along each of its highway links has been established, a process must be put in place that helps identify the best solution for each individual proposal within the highway network. Each project must therefore be subject to an appraisal. The aim of the highway…
Trip production Assume a study area is divided into seven zones (A, B, C, D, E, F, G) as indicated in Fig. 2.3. Transport planners wish to estimate the volume of car traffic for each of the links within the network for ten years into the future (termed the design year). Using land use data…
Introduction The previous model determined the number of trips produced by and attracted to each zone within the study area under scrutiny. For the trips produced by the zone in question, the trip distribution model determines the individual zones where each of these will end. For the trips ending within the zone under examination, the…
Trip generation models provide a measure of the rate at which trips both in and out of the zone in question are made. They predict the total number of trips produced by and attracted to its zone. Centres of residential development, where people live, generally produce trips. The more dense the development and the greater…
Basic principles of traffic demand analysis If transport planners wish to modify a highway network either by constructing a new roadway or by instituting a programme of traffic management improvements, any justification for their proposal will require them to be able to formulate some forecast of future traffic volumes along the critical links. Particularly in…
Any economic evaluation for a highway project must be viewed alongside its environmental and social consequences. This area of evaluation takes place within the environmental impact assessment (EIA) for the proposal. Within the US, EIA was brought into federal law under the National Environmental Policy Act 1969 which required an environmental assessment to be carried…
Introduction Highway and transportation planning can be described as a process of making decisions which concerns the future of a given transport system. The decisions relate to the determination of future demand; the relationships and interactions which exist between the different modes of transport; the effect of the proposed system on both existing land uses…
Whatever the nature of the proposed highway system under consideration, be it a new motorway to link two cities or a network of highway improvements within an urban centre, and whatever planning strategy the decision-makers are adopting (assuming that the strategy involves, to some extent, the construction of new/upgraded roadways), a study must be carried…
When the highway planning process takes place within a large urban area and other transport options such as rail and cycling may be under consideration alongside car-based ones, the procedure can become quite complex and the workload involved in data collection can become immense. In such circumstances, before a comprehensive study can be undertaken, one…
Introduction The process of transportation planning entails developing a transportation plan for an urban region. It is an ongoing process that seeks to address the transport needs of the inhabitants of the area, and with the aid of a process of consultation with all relevant groups, strives to identify and implement an appropriate plan to…