The family minibus

I have a neighbour who regularly travels with his wife and their two children. To move the four of them around, he bought a minibus with 20 seats.

'Why have you done that?' I asked, choosing my words carefully. 'There are only four of you - wouldn't a car make a lot more sense? It would take up less space and use a lot less fuel.'

He gave me a level look. 'But once every six weeks it's my turn to take my son's football team to their match. I need a vehicle with 20 seats.'

'Er, okay. But why not buy a normal car and just hire a minibus on the odd occasions you need one?' I asked. 'It would be a lot cheaper, and probably easier for you.'

'Oh, who can be bothered with that?' he replied, and stomped off.

Okay, so this neighbour is fictitious, but I've had almost exactly the same conversation with many people, with the only difference being that the numbers are all 5 times lower. There are so many people who buy a car with five seats primarily to move one person around. When challenged, they always point out some achingly unusual event as justification ('What about when I need to take rubbish to the tip?') I mean, what's that? Twice a year? Three times?

As plans for congestion charging force us to think about the consequences of our travel more and more, it is the sheer bone-crunching illogic and irrationality of this thinking that drives me crazy. Cars are fundamentally badly designed in various ways (e.g., their need for huge slurpy soft tyres to stop them flying off the road), and one of their basic design faults is that they take up the same amount of valuable road-space to convey one person as five. As I've mentioned before, people are going to have to realise that if they travel alone 95% of the time, it is better for everyone - including them - if they get a one-person vehicle and hire something bigger on the odd occasion they need more space. It's such a shame that we're going to have to go through masses of congestion and heavy-handed legislation to make people act rationally. Bah.

Road Injury Severity Map of England

Here's something curious. Using the Department for Transport's road accident statistics for 2006, I calculated road accident severity figures for each county in England. The DfT's accident figures include a Killed-and-Seriously-Injured (KSI) statistic, which is the count of the most serious road injuries: those leading to... well, death or serious injury. For each county, I divided the number of road accidents with a KSI outcome by the total number of recorded accidents. The reasoning was that the higher this ratio is, the more severe the outcomes of that county's road collisions tend to be and, in one sense, the more dangerous that county's roads are.

The statistics I computed gave figures ranging from just 5.6% of road accidents having KSI outcomes (in Plymouth, where it seems most road accidents tend to end okay) to 23.7% (in North Yorkshire, where almost one-quarter of all road accidents lead to someone being killed or seriously injured). I then normalized these values to lie on a scale from 1 to 100, converted these into saturation levels of the colour red and filled in the counties on a map. Yes, it took a few hours.

The map reveals a few points of interest:

* We have to work in call centres, but at least we don't get squashed too badly - Former heavy industrial areas around Manchester, Merseyside, the West Midlands and the Potteries stand out as having quite low accident severities.

* Leafy suburbs, dead bodies - the affluent south-western corner of Greater London suffers quite a lot of serious road accidents. It's so tempting to make a link to all the SUVs...

* Mad Crazy Viking Berserkers - North Yorkshire and the East Riding. One in four road accidents in North Yorkshire has a serious outcome. My father lives there. I'd like him to move away now.

* Wiltshire and Northamptonshire are really dangerous - I live in Wiltshire! Can everybody take more care please?

* Odd pockets of safety - Plymouth wins here, but there are other counties that stand out from their neighbours: Surrey, Rotherham, Newham in London.

Sadly, these statistics aren't broken down by county for Wales and Scotland. However, overall Wales is at a similar level to Southampton and Coventry, with just under 11% of road accidents having a KSI outcome. Scotland is somewhat worse, and with 17% of all road accidents ending in death or serious injury is similar to Essex and East Sussex.

My hope in doing this was that novel insights might reveal themselves if I looked at the accident data in a new way. I wondered if there would be a North/South split, or patterns that follow motorways. Perhaps the most striking thing to emerge here is the suggestion of more serious road accidents in rural areas. (Most notably, wherever there is a city that has separate figures from the county that surrounds it -- Reading in Berkshire, Leicester in Leicestershire, Poole in Dorset -- the city always has a lower accident severity score than the surrounding county.) This seems on the face of it to support the idea that higher levels of road crowding and reduced speeds are good for reducing the severity of road accidents, although we must also consider other factors specific to rural areas such as twistier roads which give poorer visibility, and possibly higher levels of drink-driving. But then we have to explain why Devon and Cornwall -- perhaps the most rural and twisty-roaded counties -- aren't particularly bad.

Like all good data explorations, this raises more questions than it answers, but I think it shows the value of looking at data in novel ways.

Car sharing: why can't we think beyond cars?

Car sharing is in the news again as various cities look to ease congestion by reducing the number of cars with only one person in them (four out of every five, according the the BBC report).

The BBC's article includes someone from the AA trotting out the most common objection to car-sharing, which is that it obliges people -- who often won't not know each other well -- to adjust their working patterns so they start and end work at the same time. With the sorts of jobs so many people do, this isn't possible. Therefore, people conclude, car sharing cannot work.

What a staggering lack of imagination! Why on earth don't people see that there are any number of solutions that just don't involve a car at all? It's pretty odd, when you think about it, that people spend so much time travelling alone in vehicles designed to carry five, and which fill up the road just as much to carry one person as their full complement. You wouldn't book five seats in a cinema if you were going there alone. So why don't people consider single-occupant vehicles, such as scooters and motorcycles, more often? Again, it has to be that the car is so amazingly dominant in our collective psyche that their use is totally habitual and alternatives, despite their being plentiful, much cheaper and logically more appropriate, simply never occur to people. So everybody carries on using completely, wildly, infuriatingly inappropriate vehicles to get around and our cities get less and less pleasant and accessible.

Or is it, to build on a conversation I had last night, something to do with labeling? Perhaps most people do not consider a motorcycle, for example, because they simply cannot conceive of the label 'motorcyclist' applying to them? Answers on a postcard, please.

Slippery manhole covers get the push, and not before time

Whilst cycling over the years, I've had quite a few close calls with manhole covers. When wet, or polished to a mirror-finish by thousands of passing cars, these can be as slippery as... well, I can't think of a colourful simile: as slippery as something really quite slippery that definitely shouldn't be in the middle of the road, is what I'm getting at.

One of the big problems is that because all manner of pipelines and conduits follow the same courses as the roads, manhole covers are particularly prevalent at junctions: they meet one another underground just as the roads meet one another on the surface. This is a nuisance, as junctions are already a threat to vulnerable road users and we don't need them to be made any worse. Slippery bits at a junction are a particular hazard as the turning forces make cycles and motorcycles ever more likely to fall.

In 2005 I carried out the Oxford and Cambridge Cycling Survey, and the responses we received were full of reports of people coming a cropper on manholes, so I'm very excited to learn that slippery manhole covers could soon be a thing of the past across Europe. But it's really interesting to consider why they have existed as long as they have. The clear explanation is that small slippery spots on the road just don't pose a threat to cars - if one wheel is on a slippery spot, the other three will compensate - especially on modern cars with clever traction controls that will quite literally compensate for the lost grip under one tyre. Since cars aren't affected by little slippery spots, Mr Average Public has never seen them as an issue.

When you ride a single-track vehicle, however, such as a bicycle or motorcycle, I can assure you that small slippery spots on the road are really quite a big deal. It's pretty difficult to escapable the conclusion that the problem would have been sorted decades earlier except that it was a problem only affecting minority road-users. It's one more reason why everybody should have to spend a few months cycling before they are allowed to drive. Yes, my friends: that's the master plan and I'll explain it another time.