PDC have undertaken a succession of multimode studies since the companies’ inception in 1988. Our public transport models provide a smooth interface with highway assignment models to enable particularly difficult problems to be addressed correctly under a multimodal framework. They also enable a consistent approach to appraisal across all transportation modes. Our models are capable of addressing such difficult problems as traffic restraint, decongestion, park and ride, corridor switching, parking supply, tariff structures and pricing regimes, new transport modes, significantly enhanced transport systems, policy issues, ticketing, sustainability, pedestrianisation and travel reduction targets and are capable of tackling very large and complex transport problems. Our multimodal models of the supply and demand for transport, can be applied to develop future changes to the transport system. They can be used to forecast the ridership and revenue on a transportation system and for economic evaluation. They can also be used to refine its design, optimise its operation, investigate its future target markets and assess its popularity. They also support revenue and funding decisions for private clients.
Here are some brief details about some projects we have conducted in this area.
Chelmsford Multimodal Study
Peter Davidson Consultancy (PDC) were commissioned to develop a Multimodal Transport Model of Chelmsford which could be used to test a variety of transport strategies and calculate their respective impact on modal split within the town.
A model of the road and bus network within Chelmsford was developed based upon data collected through an existing Saturn model. PDC’s Multimodal Modelling Database software pd-Mmdb was used to model the network. Mode choice coefficients were derived from PDC’s extensive library. Calibration of the model was achieved through a comparison with market research activities, which had recently been undertaken in the town.
The model produced had successfully illustrated the transport network within Chelmsford and was demonstrated to be sensitive to alterations such as bus perception, road speeds, car parking costs etc., to predict how these could affect modal split within the town.
West Midlands Multimodal Study
Date: 1999 to 2000
This project is one of a number of multimodal studies being undertaken in the UK to assess the potential for a significant shift away from car usage to more sustainable public transport and ‘slow’ modes. A key feature of the West Midlands project is that it was an area wide study of a major conurbation and had not therefore been limited to investigating mode shift within a single traffic corridor.
The role of Peter Davidson Consultancy (PDC) was to carry out the modelling and economic appraisal aspects of the study as part of a consortium of consulting firms. While this aspect of the work was being carried out within the general guidance methodologies produced by the Department for the Environment, Transport and the Regions significant adaptations and developments in methodology were required.
The basis of the modelling work was the West Midlands Strategic Transportation Model. PDC used and adapted this model and together with further work in behavioural modelling, advised on the development of alternative high-level transport strategies for the period up to 2031.
Taunton Town Studies
Following the successful completion of the Taunton Transport Strategy other towns in Somerset were earmarked for similar studies. The first two of these were the Yeovil and Bridgwater Town Studies. Each study looked at all aspects of land use and transportation in an attempt to develop an overall coherent plan for developing transport infrastructure in each town. The studies also provided evidence for scheme assessment in the county’s package bids for TPP funding.
The towns were modelled with SATURN/ TRIPS, which were extended to include a sophisticated mode choice model calibrated with a combination of stated and revealed preference data. A number of possible transport scenarios were derived from market research and thoroughly tested in the models. These, through additional group discussions, were further tested and refined down to one major scenario with some detailed variants – particularly the amount of car restraint that should be applied. These scenarios were then market-tested using stated preference, the resulting coefficients of which were used to refine the model and its forecasts for the local transport plan for each town.
The multimodal extensions of the SATURN/TRIPS models were particularly suitable for testing the viability of new or improved transport options particularly for the transfer from the private car to alternative modes. Scenarios tested included park-and-ride, improved local bus services and an extensive network of cycle ways.
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