Wednesday, 8 September 2010

Driving into Troublesome Statistics

Guernsey and Jersey's roads are seeing more and more cars. Last year the number of vehicles registered in Guernsey rose by more than 2000 to nearly 87,000. The island's population is just 62,000. In Jersey it's a similar picture. There are roughly 92,000 people living in the island, but 113,600 registered vehicles, a year on year rise of 1700. Both islands have seen the trend rising for years. In Guernsey, transport is second biggest contributor of greenhouse gas emissions environmental groups are calling for new measures to cut the amount of car use. Do you think there are too many cars in the islands? If so what do you think can be done to solve the problem? We'd love to hear your comments, post them below.(1)

I read this on the Channel Television website and couldn't believe what I was reading! If I had "any comment" to make, it would be that this is a fatuous, completely uninformative piece of reporting. It tells you absolutely nothing about car use in Guernsey or Jersey. The reporter has simply bundled together a set of figures, not all of which are coherently related to each other, and strung them together to give the impression of almost exponential increases in road use in Guernsey and Jersey, and use this wholly fabricated scenario to ask a question about greenhouse gas emissions - which is an important question, to be sure, but one which should not hang on the mish-mash of reporting that we are given.

For instance:

a) the numbers given are of "registered vehicles" - which presumably includes vans, hire cars, company cars, and may even include tractors, lorries, coaches, motor bikes, minibuses and buses. If it just referred to cars, we'd have something approaching a useful figure, and if hire cars and taxies and motor bikes could be excluded, it would be even more valuable.

b) it is clear that not all the vehicles can possibly be on the road at the same time. Of the population of 92,000, it is pretty obvious that some of those don't drive, some are too young to drive (infants and children), and even if we assume that 40,000 can drive, they obviously cannot drive all the 113,600 vehicles at once. A taxi driver may have a home runaround, and his taxi - he can't drive both at once.

c) it is true that some people who can drive and have valid driving licences may not have cars - a family may share one car between two or more drivers, for example. And some people may have the licence, but as yet no car. But if the car numbers are rising, it may be that less people are sharing cars within families, so a much better figure to use would be the number of people who hold current driving licences. At least it would give us a maximum figure of the number of road users who could be out at any one time. Have those numbers been increasing at the same rate? That would be a figure worth knowing.

d) the great days of tourism boom in the 1970s and 1980s saw the number of cars on the roads almost double when the summer season began. I wouldn't think hire cars make a huge impact on road numbers nowadays, but I imagine the figures are fairly easy to obtain. More people, of course, can now bring cars by ferry, so although not as booming as the tourism years gone by, there will be a seasonal variation, and temporary labour pools (such as workers coming in to work on the incinerator) may also increase numbers of foreign registered cars. Of course, these don't come into the figures from Channel Report at all, which is another deficiency.

In a study of "Auto-Centered Transport Systems" or ACTS, Peter Freund and George Martin note that cars provide distinct advantages over public transport.

Of course, the car is here to stay. It offers significant intrinsic advantages. The car is conveniently at one's disposal, it takes less time for linked trips, and it is capable of carrying cargo and passengers. (2)

With regard to what they note on "linked trip", Jersey - unlike Guernsey - has a radial hub through which bus users must pass, so that there is no circular trip, except when the "explorer" routes run in the summer months. Buses also have very limited room for shopping, or prams or buggies (and can refuse passengers with those if they don't have room). There's only limited room for a supermarket shop.

But they also point out that not all car trips require all these advantages, and the problem of congestion is not just to do with car use, or car ownership, but car occupancy per trip:

A large number of trips are made by solitary drivers engaged in single journeys, a substantial proportion of which are less than a mile in length.

They conclude by suggesting that while the car will remain with us for the future, what needs to be targetted is not use but overuse:

The central feature of the auto's overuse is the individuality of its use combined with built environments that encourage, even mandate, individual use. The corollary of our argument is that the best practice for a socially (and materially) sustainable form of daily transport is to concentrate on the reduction of car use by sole individuals through the construction of built environments that provide multiple and interconnected modes of transport. In such transport systems, cars remain an appropriate option, along with public transit, walking, and cycling.

Of course, this is making the best of the situation as it exists, and I am not unaware of the prophetic voices (especially locally from Nick Palmer and Daniel Wimberley) on Peak Oil, and the problems that will certainly face road traffic in the long term. So I'll end with a quote from the book "After the Car", in which Dennis and Urry warn that:

While the car system has many flaws, the key crises that will kill the car are likely to be energy availability (the end of cheap oil) and climate change (the car's undeniable role in destroying our planet's eco-system).(3)

(2) "The Social and Material Culture of Hyperautomobility" by Peter Freund and George Martin, Bulletin of Science Technology & Society 2009
(3) After the Car, Kingsley Dennis, John Urry, 2009, see also the review at


Nick Palmer said...

Of course, vis à vis climate change, the absolute numbers of vehicles registered have important significance because a big ticket purchase like a car has a large "embodied energy" associated with it, most of which is probably fossil fuel derived.

Anonymous said...

When I read the story I immediately realised that the amount of vehicles registered had no significance in road traffic or in fuel usuage.

I guess a population that lives longer would contribute to more older drivers (adds more vehicles) but not necessarily driving at peak times.

I guess a population with high GDP, being more affluent than the past will have a larger proportion of new drivers than the past and add to the problem traffic at peaks times (work/home).

I guess the problem is amplified by allowing the islands to be overcrowded compared to UK/France/Germany the list goes on.


1) Increase minimum driving age so that younger people can get used to public transport (probably be cheaper for them).

2) Restrict population growth.

3) Get more people on bikes.

Ah problem, more bikes and buses create more slow moving traffic which results in more traffic queues which may be worse than before.

Lets just ban cars.

Then everybody can get a bus, but then hundreds of buses at peak times will create traffic problems as they need to avoid all the cyclists!

I give up!!