By Chris Davey
On the coast path, this is the sign that is apt to cheer me up a bit if I’m flagging on my morning run along the cliffs, especially if the wind is in my face and I’m starting to think about breakfast.
Another project, albeit on a rather larger scale, planned and agreed before Brexit, is shortly coming to its conclusion. Anyone driving in the vicinity of the A30 Chiverton to Carland Cross will be aware of the partly EU-funded A30 dualling (much of it new road), and as I sit in the traffic queues edging forward at about 10 mph, which will of course, in time, result in speedier journeys, I ponder on various matters. Firstly, that in an EV slower speeds mean lower energy consumption (wind resistance varies as to the square of the speed), so this slow driving is increasing my range! Quite the opposite from when about half a century ago, we sat in a traffic jam in our Austin Cambridge, with my dad grumbling about how this crawling was wrecking his otherwise good fuel consumption stats.
Then, is it true that (as I read somewhere) the carbon footprint of the road construction had been drastically underrated? Now such calculations are pretty tricky to do, as there are so many variables – for example you obviously have to estimate the emissions caused by the construction work, vehicles and mostly, the high carbon footprint of concrete and tarmac. But then there’s the loss of land and trees. On the other hand, mitigation measures are quite rightly required these days, and so new trees are planted and there are industry standards for reducing some of the inevitable emissions. Then there’s a view to the future; how will emissions from vehicles using the road over the coming years be affected? What timescale should we use as the basis of these calculations? Will the vehicles cruising at about 70 mph use more or less energy than those crawling at 10 mph? That said, it’s likely that in future years many of those will be electric. It’s all rather complicated.
Here is the official version from the Planning Inspectorate.
Of course it would be rather better if, instead of driving, people took the train, and that goes for goods transport too. But though some people might embrace lower carbon forms of transport, I recall that we’ve been encouraged to take public transport (or walk or cycle) rather than drive, from at least the time when I began to take notice of environmental issues, in about 1970. But people still like to own and drive a car. Which means, in view of climate breakdown, we have to make cars as low emission as possible, and that means – at least at the moment and in the immediate future – battery electric vehicles (BEVs).
My final thought is whether being able to cruise on long stretches of motorway or dual carriageway tempts people towards UK holidays rather than a flights overseas. I have no data on that – just musing. Short-haul flights, definition up to three hours, are one of the most carbon-emitting forms of transport. I doubt that was taken into account when calculating the carbon footprint of the new road, but it just might be an unforeseen benefit.
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**Carbon emitted per passenger kilometre by various modes of transport:
Short-haul flight: 255g
Electric car: 53g
National rail: 41g
International rail: 6g
Source and more data at Our World In Data.
