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danieldwilliamI am thinking about self-driving vehicles and the impact of them on day to day life.
I am often on a bus from Chippenham to Calne so I’m using this bus route as the basis for some high-level* thinking about the impact on my life.
I’m deliberately showing my workings in case** I have made a significant error in my assumptions.
The service from Chippenham via Calne to Swindon that I use takes about 1 hour 5 minutes one way. It runs every 20 minutes from 6am until 10 pm. A 16 hour service.
Labour Costs
I think there will be 5 buses on the route at any one time, one way. Ten buses in total.
Those buses will need drivers. Ten drivers. But they don’t work 16 hours. I reckon they work 8 hour shifts. So two shifts are needed for each day. That’s 15 drivers.
The drivers will want holidays and will call in sick. I’m guessing about 15% additional headcount to cover absensce. So that’s 17 and ¼ drivers working this route. I estimate their salary including on-costs at £30k. (I’m basing this on adverts I used to see in Swindon for bus drivers.)
That’s a cost of £520k for direct labour driving the bus.
Fuel Costs
The journey is 22 miles one way.
For three buses an hour each way for 16 hours I make that 96 trips of 22 miles or 2,112 miles per day. The service doesn’t quite run every day but let’s assume it does.*** 365 days at 2,112 miles per day is 770,880 miles per year.
Deisel fuel retails at £1.42. Buses get a rebate of 43p on the fuel duty they pay so the real retail price of the fuel is closer to £0.99.****
Fuel costs therefore about £282k per annum.
Total marginal direct cost for the service £800k
So of the marginal direct costs 35% (ish) is fuel and 65% (ish) is labour. Shall we say a 3:2 ratio of labour to fuel.
Sacking all the drivers saves £520k.
If it helps let me point out that computer driven buses are going to be more fuel efficient than human driven buses. I’m allowing for a 10% fuel saving, worth £28k. This takes the total cost of the service down to £254k or 32% of its original costs. Pretty much the third of the cost.
What conclusions do I draw from this? What is the impact?
If you were to install a fleet of self-driving buses on the Chippenham to Swindon bus service and sacked all the drivers the savings from driver wages would be about the same the fuel costs for running the service, twice. Therefore you could either triple the frequency or run two equivalent service on a different route*****
Self-driving buses half or better the cost, double or triple the frequency or double or triple the coverage of bus transport in the UK.
There are some flaws with the analysis. The most significant is that in order to double the number of bus journeys you need to double or triple the number of buses. Say £100k per bus. That would be £1.6 million for my Bath to Calne route. Or the savings made in drivers’ wage for 3 years.
*EDITED*
*To update fuel cost figures for a fuel used per mile more reflective of rural driving conditions* Quite literally your mileage may vary for this post.
*Vague and almost certainly wrong but hopefully useful in a Fermi sense. Urban bus labour costs to fuel costs might be significantly different as urban buses are in stop start traffic and the density of buses per route is a bit higher (the routes are shorter and more frequent)
**In the expectation
***The buses will have to be driven back and forwards to the depot and theirs driver training and so on. Let’s call it 365 days.
**** There are other complexities to do with taxation, especialy VAT but unless you are the Tax manager at my last employer I won’t do VAT for you.
***** A Bath to Calne route would be my favourite.
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no subject
Date: 2012-02-23 01:29 pm (UTC)no subject
Date: 2012-02-23 02:37 pm (UTC)The Chippenham to Calne to Swindon route could probably easily accommodate a service frequency of a bus every ten minutes. Whether there would be the demand for a service that frequently is another matter. Certainly, there are lots of country areas where the service is very limited or non existant.
In Edinburgh you might be able to up some of the less frequent services from 30 minutes to every 15 minutes without crowding most of the route but I think there are likely to be congestion issues in the centre of Edinburgh (unless you saw a reduction in other traffic as a result of the enhanced service).
What you could add are circular or peripheral bus services. At the moment most Edinburgh services run into the middle of town and then out again. Services that ran from around the centre of town would make the overall service much more useful without adding much to congestion.
In London, I’m not sure you can increase a service frequency much from every 5 minutes.
a
Date: 2012-02-23 02:46 pm (UTC)Re: a
Date: 2012-02-23 03:08 pm (UTC)The main bottle necks of universal application would be bus stations and stops outside popular stops. Thinking about Kemble Station and replacing the hundreds of cars parked and the hundreds of drop offs by car there with a fleet of buses ferrying people from nearby villages you’d have a bit of crowded bus stop.
Thinking about this, there is a knock on effect of better public transport begetting demand for other public transport. If I can get to the station by bus now instead of car might I stop driving to work in the car and go by a combination of bus and train – requiring more trains?
I think the main boost to the quality of life from self-driving buses is in the country. Talking to my mum who was involved in a study about how people could get to a hospital appointment in her hospital by public transport the
A fleet of small, self-driving buses pottering about the Cornish countryside on a twenty minute cycle would seem to be a great improvement over a service that had a few dozen routes served hourly.
Re: a
Date: 2012-02-23 03:45 pm (UTC)Supply and demand can also be regualted better, in that you don't run empty buses. Will continue this down below...
Re: a
Date: 2012-02-23 04:51 pm (UTC)Buses operating along a main road– press a button on a bus stop in your local village and the next bus along diverts to collect you. Most buses won’t stop at most stops. If those buses can avoid actually going into those villages then average journey times and fuel use are both reduced.
In cities there might be more scope for smaller buses that wandered along a corridor (say Morningside to the East End of town via the south of the Meadows) and responded to calls from bus stops spread out all over the place. With a service running at five minute intervals there would be loads of buses going near enough to where you wanted to go that you would ever be waiting long even if the next bus along wasn’t able to divert to collect you.
I have a science fiction short story in draft (very early) about a couple trying to get somewhere using an intergrated public transport system that self-optimises and which as got caught on the cusp of two solutions to its current demand and keeps flipping from one to the other.
no subject
Date: 2012-02-23 02:41 pm (UTC)For real world consequences, I'd compare this to what happened when buses went from two-man to one-man operated, when all the conductors got sacked.
So, Michael, what happened when buses went from two-man to one-man operated, when all the conductors got sacked in Glasgow?
Fares stayed the same. Journey frequency stayed the same. No new routes opened up (there's an argument that some routes stayed open that would otherwise have closed sooner).
Vandalism and anti-social behaviour on buses went up (with no conductor to keep the peace, so fewer people used the service.
My guesses, sorry, first order aproximations, would be that no new buses would be bought before the current fleet reached their planned end of life, so we're looking at the difference between a standard and driverless replacement, or, possibly, some retro-fitted kit to existing fleets.
This is driving me (sorry) into thinking about the economics of bus companies. Much like trains, they seem to be reliant on Government franchises. Demand for the service doesn't seem to have a correlation with supply (I heard Coalition politicians talking about how you solved overcrowding on trains by raising ticket prices recently). It seems to me that any reduced costs would not be used for extra services, but to increase profits. Woo hoo!
no subject
Date: 2012-02-23 03:18 pm (UTC)I think the important bit of data missing from your comment is how many routes stayed open that would otherwise have closed.
Hidden in this is the question of subsidy. How much subsidy were the buses attracting? How much of this subsidy was reduced and handed back to tax payers instead of spent on additional services? Difficult to tell.
We could see no more routes opened up but a big reduction in subsidy. Which would not be a bad thing but it wouldn’t be my favourite thing to do with the saving.
The issue of crowd control, anti-social behaviour and collection of fares is one to puzzle over.
Mind you, the survielance opportunities now available to bus companies coupled with the fact that if you are on a self-driving bus you have just stepped onto a moving prison might make serious anti-social behaviour less of a problem.
I think we would see wholesale replacement of buses. The savings from replacing a bus (and driver) mid way through its live with a self-driven bus are I think strongly NPV positive. Especially, if you can persuade / con some city in India to take the old buses off your hands for some money.
no subject
Date: 2012-02-23 03:49 pm (UTC)Yup, the routes staying open is interesting, but from observation routes closed anyway. The subsidy rules would need to be known - the minimum you have to do to collect your subsidy becomes the performance target.
Wider question is, why is their a subsidy? Especially if the subsidy is larger than the cost of the local authority providing the service.
And with buses as moving prisons, you've taken me into the realm of 2000AD, and Judge Dredd.
no subject
Date: 2012-02-23 04:27 pm (UTC)(other than the partial fuel duty relief).
I guess the subsidy is to cover the periods of the day when the cost of running an individual bus is greater than the revenues that that particular bus generates but where the bus is required to make the overall service worth having or to provide a social service for those without cars.
The subsidy from Edinburgh Council to Lothian buses looks to be about £1m on a turnover of about £112m. I think the situation in rural areas is much more weighted towards a subsidised service.
no subject
Date: 2012-02-23 04:43 pm (UTC)no subject
Date: 2012-02-23 04:52 pm (UTC)Certainly, they would be if you didn't have to pay for a driver.
Also, buses after mid-night - no driver, no anti-social working shift allowances.
no subject
Date: 2012-02-23 04:36 pm (UTC)no subject
Date: 2012-02-23 04:43 pm (UTC)no subject
Date: 2012-02-23 05:08 pm (UTC)This is a 44 seat ARIVA Hybrid auto-drive bus and seeing as it will revolutionise urban transport the question you got to ask yourself is, do I have an appropriate funding mechanism?
Well, do ya?
no subject
Date: 2012-02-23 03:24 pm (UTC)Raising supply might be difficult where the marginal cost of additional supply is greater than the marginal revenue from additional journeys. In railway engineering terms I can see that this might be the case on parts of the UK rail network where significant capital costs (which are hard to divide) are required.
The other solution is to reduce demand. This can be done by providing substitutes or by raising the price. Substitutes suffer the some of the same infrastructure provision issues, depends how you do them. (I’d vote for self-driving buses). Raising the price is easy. Not so good if you are a punter.
Buses I think suffer from this problem less so.
For the price of a dozen buses I could start a Bath to Calne bus service. I don’t need to spent millions upgrading stations or laying track or upgrading signalling.
no subject
Date: 2012-02-23 03:55 pm (UTC)But this is systems thinking. Buses are for making money, and a bus service can only be viable if it is profitable. Even with the financial subsidies given, service provision is drawn towards the minimum standard which still gets your subsidy paid.
In ye olden days of the 1970s and 80s, Glasgow had an integrated transport policy covering trains, subway, buses and even the odd ferry or two. That was broken up in the 80's in the interest of lessening council powers.
I wonder how that worked out?
no subject
Date: 2012-02-23 04:33 pm (UTC)One might suggest a funding model where indivual passengers pay what the service is worth to them through a ticket and society as a whole, through local authorities, pay what a good bus service is worth to society as a whole.
I think those funding arrangements look similar to the current funding arrangements.
Again, I think one is stumbling into the seductive power of the Thatcherite mindset when considering bus routes individually, or bus services on their own.
However, I'm unclear how else to tell if a bus service (route or in toto) is valuable to local citizens without using a ticket price (in the absence of more direct democracy0.
no subject
Date: 2012-02-23 04:45 pm (UTC)Journeys are already unmetered for pensioners - maybe they should be unmetered for all, and funded directly from taxation.
no subject
Date: 2012-02-23 05:05 pm (UTC)But how to tell if the service provided is the one most wanted? Or if service that is little used by members of a community is actually really valued by them because it means that the dozen pensioners and the dozen teenagers in their village have access to the wider world without needing a lift from mum?
Actually, this raises an interesting point about self-driving cars.
If I'm not driving, do I need a license? If BB at 14 isn't driving does she need a license? Could she just hope in the car and tell it to take her to Nando's.
What about the Capt? Could I pop him in the car, send it to Grandad's and have Granddad meet it in his garage?
no subject
Date: 2012-02-23 04:36 pm (UTC)So long as increased council powers are matched by increased voter power.
I wouldn't want to make public transport the sole preserve of local council though. I think the ability of a aggrieved and enterprising locals to say "You know what, I could do better than these monkeys, and I will."
For example Free Bus in Bristol.
http://www.freebus.org.uk/
no subject
Date: 2012-02-23 04:46 pm (UTC)no subject
Date: 2012-02-23 05:15 pm (UTC)I'm cautious unfettered power in monolithic organisations. When they are privately owned I want the state to be able to step in with regulation or competition.
When they are state owned I want the ability for the private sector to sidestep the state.
Mainly, I want the ability for people to vote with their feet if the service they are getting isn't what they need.
no subject
Date: 2012-02-23 05:11 pm (UTC)Poor, can't afford a car? Or are you visually impared, epileptic or born with wrists too weak to steer?
Don't worry, there will be a bus along in a few minutes that will take you to the library, the shops, your local MSP's office, your community group or sports club.
no subject
Date: 2012-02-24 12:23 pm (UTC)On the other hand you will have to hire people who can maintain the brain parts of the self-driving buses, which might be on top of the people who maintain other bus parts. There are presumably also costs related to installing the self-drive system, and the bus company would also need a solution to selling and checking tickets. Self-driven buses may also have problems associated with managing the behaviour of bus users and reacting to emergency situations on board (I imagine they would have to be able to react to emergency on-road situations in order to classify as "self driving").
no subject
Date: 2012-02-24 01:03 pm (UTC)I’ve deliberately not included those because I don’t know enough about the organisational structure of bus companies and the indirect costs could be significantly more or less than I would guess.
Gut feel, the indirect on-costs would be on the low side. We’re talking a fairly homogenous skill set doing fairly routine work so I don’t imagine huge training or back office requirements. But I don’t know.
I’m rolling up the costs of the self-driving system into the capital costs of a new set of buses.
The problems that I think are going to be difficult to sort out are the ones you mention on behaviour of the passengers on the bus. What does the bus do if someone has a heart attack? A bus with a driver might drive to the nearest hospital. Do you install an emergency override? If so, how do you stop idiots hitting it every couple of minutes? Who is the designated leader of the hierarchy and therefore able to tell other people to turn down their ghetto blaster?
There would be software support and some extra hardware to service - and people with the skills to do that will be more expensive to employ than drivers but I think you would need many fewer of them than one per bus.
no subject
Date: 2012-02-24 02:42 pm (UTC)no subject
Date: 2012-02-24 02:56 pm (UTC)From looking at the Lothian buses annual report I am guessing maintenance teams are a relatively small part of the overall cost of running a bus route. But I’m guessing here.
Garaging cost likewise increase unless you run the buses 24 hours a day or park them up in bus stops overnight (which you could do because you don’t have a driver who wants to get home from where he parked his car).
no subject
Date: 2012-02-24 06:10 pm (UTC)But the important thing to my mind was that it changed the frequency from every 10-20 minute to every 5-10 minutes (in practice, because routes overlap so much, you're normally looking at a maximum 5 minute wait before you get something going in roughly the right direction). That's a hugely significant psychological change in useability. If I'm facing waiting at a bus stop for 20 minutes then I'll drive, or get a convoluted tube or rail journey or take any other choice I have. If I think it's going to be 5 minutes, 10 maximum then I'll go for the bus, especially if it's cheaper, which it is.
The other factor, and the reason he did it, was that the tubes were (and still are) literally full to bursting. At rush hour (roughly 4 hours a day) they run once a minute, and there is no space for any more people at all on many lines. Only buses could increase capacity fast enough to keep the city moving and stop people taking to their cars in desperation (along with congestion charging and increased bike and scooter use of course). And of course there's no point in driving into the centre if finding a parking place is going to take you half an hour when you get there.
The problem with taking the same approach in the countryside is that doubling or trebling frequency normally still leaves service at a level where you won't use it if you have a choice - if service moves from every 2 hours to every 40 minutes then that's excellent news for the people who don't have a choice, but most of the people who do have a choice will still keep driving.
[drifted over here from Andrew Ducker's links]
no subject
Date: 2012-02-27 10:25 am (UTC)I think that’s a sound point on the frequency of buses.
In lots of cities in the UK I think doubling the frequency of the buses would begin to have a service that hit your magic 5-10 minute waiting period.
I do think there is a large group of people in the country who don’t have a choice or for whom having a choice is very expensive. With car insurance premia at a couple of grand for a new driver a decent 24 hour a day bus service for rural kids would be really useful.
You certainly need to get them some combination of frequent enough and cheap enough that communting by them is feasible.
When I worked on an industrial estate in the country I was hugely frustated that the only bus that served both the estate and the station I had got off at was an hourly service that left the station five minutes before my train arrived and stopped running at 6. No use to me to help me get to work on rainy days. Doubling the frequency and extending the service by an hour would have seen me on that bus often.