The Government consultation on this subject issued in June was responded to by LGTAG in writing and at a recent Landor Conference. Members of LGTAG were consulted during the response.
The main issues seen bus and expressed at the Landor Conference were:
- We understand the 5 Webtag cases and also the need to satisfy the Treasury with the present funding arrangements
- Webtag is very complex and opaque
- There is enormous scope for inaccuracies
- Except in largest authorities there is a need to appoint expensive consultants
- The highest benefit/cost interventions (eg bus lanes, parking enforcement etc) are not favoured over road schemes
- For road schemes ‘economic benefits’ are of little real benefit to society (peak times and 30- 60 years in future)
- There is little confidence that centre (Whitehall and Westminster) can understand or know what works best locally
- The benefits are usually calculated as a small difference between two enormous sums of time spent on network – this is mathematically unsound
- There are a multitude of sometimes spurious assumptions (e.g. speed flow curves with unlimited capacity, assumed speed on minor roads, no measures of extra traffic and congestion from generated traffic outside study area)
- Modelled traffic assigned to roads is sometimes factors out
- Behavioural value of time may be important for modelling but peak hour car travellers time of little ‘societal’ value
- Then — how accurate are the COSTS of the intervention especially for large road and rail schemes?!
Our full submission is attached LGTAG-Response-to-DfT-Appraisal-and-Modelling-Strategy.pdf (704 downloads )
