全球智库信息集成服务系统

How well did the mode-destination models transfer to the South East Wales context?

• Overall the transfer process worked well. For four of the home-based purposes the transfer parameter was close enough to one to be fixed to one implying that the mode-destination models have the same explanatory power in the West Midlands and South East Wales contexts. For three of the purposes scale parameters significantly lower than one were identified but the lowest of these was 0.6. For non-home-based purposes, two of the scale parameters were 0.5 and 0.4, and the rest of the parameters were fixed to one.

How well do the models replicate observed travel behaviour in South East Wales?

• The ability of the models to reproduce the mode shares observed in the local household interview data was assessed. This analysis demonstrated a close match between observed and predicted mode shares for each model purpose.

How do the model sensitivities compare to WebTAG realism test guidance?

• The sensitivities of the models to fuel cost changes are low relative to the WebTAG guidance, with an overall kilometrage elasticity of -0.17 compared to the -0.25 to -0.35 WebTAG range. The car time elasticities are all consistent with WebTAG guidance as are all but two of the public transport fare elasticity values (these two purposes account for less than 2% of public transport trips).
• These elasticities were calculated from the unweighted model estimation sample as a check that the demand models respond reasonably to changes in costs and times. Definitive elasticity values can be calculated from base year runs of the model implementation which will be based on estimates of the whole population and will take account of congestion impacts.