Smarter Cambridge Transport

Why not to trust transport forecasts

Leafing through the Guided Busway Order Transport Assessment (yes, I read these scintillating documents so you don’t have to), I was struck by just how badly wrong the forecasts were.

Engineering consultant Atkins forecast 20,304 daily trips in 2016. Discounting trips from Northstowe (only now being built) reduces it to about 17,000 trips. The actual figure reported for 2016 was 10,350 – and that includes trips not included in the forecast, such as between Peterborough and Huntingdon. Why isn’t the Busway more popular when the stress and uncertainty of driving along the A14 have never been worse?

The journey from St Ives to the Science Park, entirely on the busway, was predicted to take 17¼ minutes; it actually takes 25–35 minutes. From Huntingdon to Cambridge city centre was predicted to take 44–51 minutes; it actually takes 68–78 minutes, significantly longer than the 55–67 minutes before the busway was built.

Atkins claimed, “Fenstanton would be likely to be served by 3 buses per hour … to Cambridge in the morning peak.” Hear the distant sounds of tea being snorted in startled derision? Fenstanton now has just two direct buses a day to Cambridge, and a worse-than-hourly service if you change at Bar Hill.

The total cost was meant to be £86.5m in 2002 prices. Allowing for construction inflation, that would have become £108m by the time work began in 2007. The cost in fact ran to £152m. Since then the County Council has so far incurred £7.2m for repairs, investigations and legal fees, which it hopes to recoup from the constructor, BAM Nuttall, along with at least £36.5m for further recommended urgent structural repairs. So the busway could yet cost double Atkins’ adjusted estimate.

The scheme was rated ‘high value for money’, based in large part on journey time savings – including on the A14, owing to the decongesting effect of the Busway. More realistic costs and benefits would have given the scheme a ‘poor value for money’ rating, which would not have qualified for taxpayer funding. I wonder if there was a better way to spend our money?

This article was first published in the Cambridge Independent on 22 August 2018.

Edward Leigh

Edward Leigh is the leader of Smarter Cambridge Transport, chair and independent co-opted member of the Cambridgeshire Police and Crime Panel, chair of the South Petersfield Residents Association, business owner, consultant, and occasional blogger about making the world and Cambridge a better place to live.


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  • Wasn’t the guided bus meant to be a cost effective alternative to reopening the old railway line?

    • Yes – promoted IIRC by bus/road ideologues.
      The real irony is that 1922’s trains were fater than the buses right now.