At the end of March, the UK Department for Transport issued its "Transport Carbon Reduction Delivery Plan".

A major problem I have with it is the downbeat attitude to freight transfer from road to more benign modes. This is typified by the use of statistics which, while no doubt true and accurate, are downright misleading. Moreover they've been known to be misleading since the mid 1970s.

The report, on page 64, says that, "68% of all road freight movements (measured by tonnes lifted) are within the same region and so are unlikely to have a viable mode shift option".

Let's set aside the fact that historically some of the heaviest freight flows in the country - by tonnes lifted - have been within the same region: these are flows of coal for power stations.

But let's look at two important factors.

First, we're talking carbon reduction. And that is a function, not of tonnes lifted, but of tonne-kilometers moved. 100 tonnes moved 20 kilometres use a lot less carbon than 100 tonnes moved 200 kilometres: you need the distance factor to measure the potential importance. Tonnes lifted is irrelevant.

Second, in 1974 a book called "Changing Directions" was published (and I remember, as a post-graduate student at Birmingham University, meeting some of the team who wrote it). This showed the the importance of distance very vividly on page 229.

The then Department of the Environment had calculated that the maximum amount likely to be transferred from road to other means was only 1.5%, based on the average length of haul of road freight travelling over 25 miles.

However, "Changing Directions" made the point that, if there was a mode transfer away from road of 60% of the road freight in the 150 miles and over range, 40% in the 100 - 149 mile range and 30% in the 50-99 mile range, the figure would be very different. About a quarter of all road tonne miles would be removed to other modes.

"Those who cannot remember the past are condemned to repeat it" (George Santayana).