Towards the Sustainable City: The Impact of Land Use – Transport Interactions. A Comparison of the impact of the initial and final coefficients on location choice on transport strategies and land use scenarios.

Over the last decade the concept of integrated transport strategies for urban areas and a means of evaluating them have been developed and widely accepted into practice by major studies of cities such as London (May and Gardner, 1990), Birmingham (Wenban-Smith et al, 1990) and Edinburgh (May, Roberts and Mason, 1992). The development of integrated transport strategies (May, 1991) has been based on the identification of synergy between transport policy instruments (May and Roberts, 1995). These concepts led indirectly, particularly through experience in Birmingham, to the introduction by the Department of Transport of the Package Approach for urban transport funding (May, 1994a) and more directly to the development of the Common Appraisal Framework for assessing Package Approach bids (MVA et al, 1994). It is now generally accepted that transport strategies designed to meet the objectives of economic efficiency and sustainability will require a combination of measures to manage the existing infrastructure more effectively, to provide selective enhancements to that infrastructure and to impose appropriate pricing mechanisms on both public and private transport. In a recent study, funded by EPSRC, we have developed a methodology for identifying optimal specifications for such strategies, and have shown that their performance is particularly sensitive to the contribution of pricing measures such as fares and road pricing (May, Bonsall, Bristow and Fowkes, 1995). However, while we are now able to formulate optimal transport strategies, very few studies have been able to demonstrate that transport policy measures alone will achieve a sustainable situation in which fuel consumption and emissions are maintained at or below current levels (May and Roberts, 1995). In most cases, land use changes will need to be co-ordinated with transport measures if sustainability is to be achieved, and recommendations for appropriate land use measures are beginning to emerge (DoE, DoT, 1993; DoE, 1994). An initial assessment of the potential for co-ordinating transport and land use strategies was carried out using the results of the Edinburgh study (Still, 1992), and showed that the preferred transport strategy would be up to 10% more effective in achieving sustainability when combined with a concentrated land use strategy. However, that study assumed no feedback from transport measures to land use effects. Literature reviews and interviews have demonstrated that the impact of transport on land use is perceived as a serious gap in policy understanding. Interviews also revealed that land use-transport models are treated with some scepticism, because there is insufficient understanding of the relationships within them and because the existing models are perceived as unduly complex (Still, 1996). As a result of this lack of understanding, there is a danger that impacts of transport on land use might have counter-productive effects on the land use - transport strategy. For example, road pricing, which may be a key element in a sustainable transport strategy (May, 1994b), may reduce accessibility by private car, and hence lead to outmigration of business, thus producing a less sustainable land use pattern. Conversely it could enhance the city centre environment, and hence encourage certain firms to relocate to the centre. These twin impacts of transport policy on accessibility and on environmental quality are the key elements in predicting the resulting location decisions of individuals and firms, and need to be better understood if sustainable land use - transport strategies are to be developed. The principal objectives of the project are : (i) to increase our understanding of the impact of accessibility and environmental quality on individuals’ and firms’ location decisions; (ii) to use the findings of (i) to enhance a newly developed strategic transport and land use interaction model; (iii) to use the enhanced model to assess the implications for urban sustainability of the impact of transport policy on location choice; (iv) to use the enhanced model to assess the relative performance of different combinations of transport and land use strategy

Towards the Sustainable City: The Impact of Land Use – Transport Interactions. The impact of accessibility and environment coefficients in location choice on transport strategy performance.

Over the last decade the concept of integrated transport strategies for urban areas and a means of evaluating them have been developed and widely accepted into practice by major studies of cities such as London (May and Gardner, 1990), Birmingham (Wenban-Smith et al, 1990) and Edinburgh (May, Roberts and Mason, 1992). The development of integrated transport strategies (May, 1991) has been based on the identification of synergy between transport policy instruments (May and Roberts, 1995). These concepts led indirectly, particularly through experience in Birmingham, to the introduction by the Department of Transport of the Package Approach for urban transport funding (May, 1994a) and more directly to the development of the Common Appraisal Framework for assessing Package Approach bids (MVA et al, 1994). It is now generally accepted that transport strategies designed to meet the objectives of economic efficiency and sustainability will require a combination of measures to manage the existing infrastructure more effectively, to provide selective enhancements to that infrastructure and to impose appropriate pricing mechanisms on both public and private transport. In a recent study, funded by EPSRC, we have developed a methodology for identifying optimal specifications for such strategies, and have shown that their performance is particularly sensitive to the contribution of pricing measures such as fares and road pricing (May, Bonsall, Bristow and Fowkes, 1995). However, while we are now able to formulate optimal transport strategies, very few studies have been able to demonstrate that transport policy measures alone will achieve a sustainable situation in which fuel consumption and emissions are maintained at or below current levels (May and Roberts, 1995). In most cases, land use changes will need to be co-ordinated with transport measures if sustainability is to be achieved, and recommendations for appropriate land use measures are beginning to emerge (DoE, DoT, 1993; DoE, 1994). An initial assessment of the potential for co-ordinating transport and land use strategies was carried out using the results of the Edinburgh study (Still, 1992), and showed that the preferred transport strategy would be up to 10% more effective in achieving sustainability when combined with a concentrated land use strategy. However, that study assumed no feedback from transport measures to land use effects. Literature reviews and interviews have demonstrated that the impact of transport on land use is perceived as a serious gap in policy understanding. Interviews also revealed that land use-transport models are treated with some scepticism, because there is insufficient understanding of the relationships within them and because the existing models are perceived as unduly complex (Still, 1996). As a result of this lack of understanding, there is a danger that impacts of transport on land use might have counter-productive effects on the land use - transport strategy. For example, road pricing, which may be a key element in a sustainable transport strategy (May, 1994b), may reduce accessibility by private car, and hence lead to outmigration of business, thus producing a less sustainable land use pattern. Conversely it could enhance the city centre environment, and hence encourage certain firms to relocate to the centre. These twin impacts of transport policy on accessibility and on environmental quality are the key elements in predicting the resulting location decisions of individuals and firms, and need to be better understood if sustainable land use - transport strategies are to be developed

Towards the Sustainable City: The Impact of Land Use - Transport Interactions. The development of revised location coefficients.

This paper gives an outline of the steps undertaken to convert from the willingness to pay for travel time savings, air quality and noise derived in tasks 3 and 4 to the location coefficients for use with the DELTA/START model

Area Speed Flow Relationships:The Effect of Varying Signal Capacity

This paper is one of a series of ITS working papers and technical notes describing the methodology and results of the EPSRC funded project "The definition of capacity in urban, road networks : The role of area speed flow relationships". The objectioes of the project were to investigate the interaction between vehicle-hours and vehicle-km within a network as the demand for travel increases; to develop improved area speed flow relationships; to use the relationships to explain the process by which networks reach capacity; and to assess the significance for the evaluation of road pricing policies. The approach used was to collect the vehicle-hours and the vehicle-km directly from a simulation model and thus create relationships between supply and demand in terms of veh-hours/hr and veh-km/hr demanded and also between times per trip and trips demanded. During the project two models were used. The first was a micro-simulation model called NEMIS. This model was used on hypothetical networks ranging from single link to a six by six grid and finally a ring-radial network. The networks were used to study the effects of changes in OD pattern and the effects of varying capacity on the resulting speed flow measures. The second model used was SATURN. This model was used to study the same ring-radial as before and a full SATURN model of Cambridge. The SATURN results were then taken one step further in that they were used to create an aggregate model of each network using SATURN in buffer only mode. The related papers discuss issues such as network aggregation. Note that the methodology and terminology was developed as the study progressed and that in particular the method varies between application of the two distinct models. The reader is directed to the attached appendix A for a full list of publications arising from this project

Toroidal Imploding Detonation Wave Initiator for Pulse Detonation Engines

Imploding toroidal detonation waves were used to initiate detonations in propane–air and ethylene–air mixtures inside of a tube. The imploding wave was generated by an initiator consisting of an array of channels filled with acetylene–oxygen gas and ignited with a single spark. The initiator was designed as a low-drag initiator tube for use with pulse detonation engines. To detonate hydrocarbon–air mixtures, the initiator was overfilled so that some acetylene oxygen spilled into the tube. The overfill amount required to detonate propane air was less than 2% of the volume of the 1-m-long, 76-mm-diam tube. The energy necessary to create an implosion strong enough to detonate propane–air mixtures was estimated to be 13% more than that used by a typical initiator tube, although the initiator was also estimated to use less oxygen. Images and pressure traces show a regular, repeatable imploding wave that generates focal pressures in excess of 6 times the Chapman–Jouguet pressure.Atheoretical analysis of the imploding toroidal wave performed using Whitham’s method was found to agree well with experimental data and showed that, unlike imploding cylindrical and spherical geometries, imploding toroids initially experience a period of diffraction before wave focusing occurs. A nonreacting numerical simulation was used to assist in the interpretation of the experimental data

PROJECT OPTIMA: optimisation of policies for transport integration in metropolitan areas

The overall objectives of Project OPTIMA were: (i) to identify optimal urban transport and land use strategies for a range of urban areas within the EU; (ii) to compare the strategies which are specified as optimal in different cities, and to assess the reasons for these differences; (iii) to assess the acceptability and feasibility of implementation of these strategies both in nine case study cities (Edinburgh, Merseyside, Vienna, Eisenstadt, Tromsø, Oslo, Helsinki, Torino and Salerno) and more widely in the EU; and (iv) to use the results to provide more general guidance on urban transport policy within the EU

Guide Field Dependence of 3D X-Line Spreading During Collisionless Magnetic Reconnection

Theoretical arguments and large-scale two-fluid simulations are used to study the spreading of reconnection X-lines localized in the direction of the current as a func- tion of the strength of the out-of-plane (guide) magnetic field. It is found that the mech- anism causing the spreading is different for weak and strong guide fields. In the weak guide field limit, spreading is due to the motion of the current carriers, as has been pre- viously established. However, spreading for strong guide fields is bi-directional and is due to the excitation of Alfv\'en waves along the guide field. In general, we suggest that the X-line spreads bi-directionally with a speed governed by the faster of the two mecha- nisms for each direction. A prediction on the strength of the guide field at which the spread- ing mechanism changes is formulated and verified with three-dimensional simulations. Solar, magnetospheric, and laboratory applications are discussed.Comment: 9 pages, 6 figures, Submitted to JG