James Barlow

South Gloucestershire Conservatives, the minority administration on their local council at the moment, are developing some great ideas for improving the transportation infrastructure in the area. While Bristol City Council are pondering the high-risk, high-cost approach of Bus Rapid Transit, the South Glos team have come up with a plan that will - without question - improve traffic flow. And it won't cost a penny.

The proposal, which is currently under review, is to liberate the peak "2+" lane on the A4174 Ring Road (technically not a ring), and let all vehicles use the road space.

"2+" lanes, or High Occupancy Vehicle lanes are a controversial approach to traffic management. In theory, they offer an incentive to drivers to self-organise such that the road is used by fewer vehicles, and thus reduce congestion. In practice there is very little evidence that they do anything other than introduce further "choke points" and make roads even more congested. But, there is at least anecdotal evidence of an increase in mannequin sales.

For all the talk of encouraging (i.e. forcing) people to change their behaviour, there is often little desire amongst planners to acknowledge the logical reasons why people behave as they do.

Our society has evolved to take advantage of the availability of personal vehicular tranport usage and our cities, towns and suburbs have adapted to suit people who use cars. Our choice of job, home and even leisure pursuits are linked in a chaotic web of opportunity costs, trade-offs and personal preferences.

In the Joint Local Transport Plan - the holy text of the high priests in the Urban Traffic Management & Control suite - a vision of the future of private motoring is offered:

• Recognise the important role of the car in providing essential mobility for many people.
• Manage car use as part of an integrated package of complementary measures.
• Reduce car-dependency by promoting viable alternatives.
• Reduce the environmental, financial and health costs of private motoring.
• Car strategy and the Shared Priorities
• Provide attractive alternatives so that people can reduce their dependence on the private car.

Notice the framing of private car ownership with the terms of substance abuse problems. Cars are recognised as providing "mobility", but the message is really that personal transport needs to be managed; that people are dependent on private motoring and suffer health costs, in a paradigm taken straight out of the Sociology text books.

Certainly behaviour does change in response to circumstances, but not quickly. And the ability of people to change their behaviour in response to such centrally planned action is often constrained by other bits of central planning.

Transport Planning - From "A" to "B"

Let's play at planning and do a little thought experiment, by modelling different types of journey. Consider someone who lives at Point "A" and works at Point "B" with two "modal options":

• Private Motor Vehicle (20 minutes journey duration)
• Mass Transit (35 minutes journey duration)

In this model, the individual making the choice might regard the bus as quite an attractive option; it takes a bit longer but you could just sit and read the paper. It's not a very good model, however, since it doesn't tell us much about real world behaviour. Let's make it a bit more complex:

• Through the influence of other road users, the car journey from A-B takes 20 minutes on average, but sometimes it can take as much as an hour due to traffic congestion
• The bus uses a dedicated BRT lane, so it has a predictable journey time
• The nearest bus stop is a short walk from home
• The buses run reasonably regularly, so the wait for the next bus is reasonably short and typically 4 minutes (this is only a quick blog post; life is too short for a Poisson distribution.)

The individual traveller has a choice is between 15-60 minutes in the car versus a predictable 41 minutes on the bus. What about another iteration?

• Citizen #1 marries Citizen #2, producing Citizen #3
• Citizen #1 gets a new job working at Point "C"
• Citizen #2 works at point "D"
• Citizen #3 attends school at point "E", dropped off by #1 in the morning, picked up by #2 in the evening.
• Citizen #1's elderly Mother lives at point "F", and he drops in to see her on the way home.
• Citizen #3 attends an after-school Ballet class at point "G"

In this scenario, the fact that a BRT route exists between A and B is not particularly helpful. And we haven't even begun to talk about money.

The two adults in this model might wish to move closer to where they work, but the Stamp Duty Land Tax on the property sale is a disincentive to this adaption, even if they could afford a house when the prices are driven up by restrictive town planning legislation (q.v green-belt vs brownfield). They might choose to send Citizen #3 to a school within walking distance of home, but none of the nearby state schools have good reputations. Citizen #1's mother could perhaps move closer, but if Mum was sensible and saved all her life, she'll has to pay all her own care costs due to means-testing, to say nothing of the Death Tax.

That's the trouble with central planning. Whether it be transport, schools or society, grand plans made from on high tend to run afoul of the laws of unintended consequences.

Planning and Directing OR Experimenting and Adapting

Perhaps we'd be better of with a bit less strategic planning. But then there'd be no need to employ strategic planners. The Government Office of the South West paid Atkins to continue this exercise for the million or so people in the Greater Bristol "Go-to-Work" area. Two years later, the result was the Greater Bristol Strategic Transport Study, which is the Joint Local Tranport Plan with extra brass knobs fitted. No planning means no consulting jobs.

It will be interesting to see how the road network will responds to opening up the 2+ lane will be. I wonder if there are any similar initiatives we could try in Bristol? Perhaps we could experiment with the "Naked Streets" concept: turn off a few sets of traffic lights and see what happens.

Late News - Stephen Williams enquires about higher taxes

Stephen Williams MP continues the collectivist (Lib Dem) crusade to squeeze the last bit of cash out of hard-working Bristolians by asking the following question in Parliament:

To ask the Chancellor of the Exchequer how much revenue would be raised by an additional one per cent. on the basic rate of income tax in the fiscal year (a) 2007-08 and (b) 2008-09.

For Christ's sake, man, don't give them any ideas!

The answer he is given refers to an HMRC table of Direct Effect of illustrative tax changes. These tables imply a linear relationship between tax rates and tax revenue, although a concept known as the Laffer Curve proposes elasticity, which matches common sense in that if tax rates were lower people would spend less time and money avoiding the revenuers, and thus tax revenues would actually be proportionally higher. I hadn't realised that this concept dates back as far as the 14th century and is mentioned in the work of noted Arab historian Abu-Zayd Abdul Rahman bin Muhammad bin Khaldun.