Will autonomous vehicles have enough energy for all that thinking?

It doesn’t feel like thinking uses all that much energy, does it? If we want to lose weight, we’re told to go for a run, not play chess.

However, evolutionary biologists have pointed out that our current, oversize brains did not evolve until after we mastered the use of fire to cook our food. That’s because they use a surprising amount of calories. Our nearest primate cousins, with their raw food diets, simply don’t have enough hours in the day to eat and digest all the calories that it would take to support a human brain. Cooking means we can extract more calories from the same amount of food, more quickly.

Is the same true of electronic brains then? Well, there was a great story in the press recently about a swimming pool in Exmouth that is being heated with the waste heat from just a small part of a data centre. A data server the size of a washing machine is enough to heat the pool to 30C around 60% of the time. So yes, all those transistors may not look like they’re doing much, but they are using a huge amount of energy.

What might this mean for autonomous vehicles? It’s generally taken as a given that most autonomous vehicles will be electric, since that’s the way we’re going. And EVs already have a problem with energy storage. If the vehicle also has to do its own thinking, what might that do to its range?

I should credit the Emissions Analytics blog for first alerting me to this question. Back in 2020 they did a few ‘back of the envelope’ calculations, and came to the conclusion that a fully autonomous vehicle, with multiple sensing and processing systems, might use as much energy to do its sensing and ‘thinking’ as it needed to actually drive the wheels.

That, frankly astonishing, conclusion suggested this might be a bigger problem than one might think – even if Emissions Analytics’ calculations were a fair way out. At the time I wondered if any other evidence might back this up.

Then last year I went to visit some guys in a start-up based in Millbrook, called Hypermile AI. They were kind enough to take me around the Millbrook bowl in an HGV tractor unit that was basically being driven by a mobile phone. Their very clever kit combines with the truck’s cruise control to anticipate the movement of other vehicles much better than the usual crude adaptive cruise control algorithms, thus achieving fairly impressive fuel savings.

While we were chatting after the demonstration, I asked about the energy use of fully autonomous systems – could they be as energy hungry as Emissions Analytics had suggested. The reply – ‘absolutely’. That’s one of the reasons the Hypermile System only uses a single camera – as soon as multiple sensing systems need to be integrated into that type of system, the processing power (and associated energy use) increases exponentially. Anecdotally, they told me that many Tesla drivers report that when they are using full autopilot, the range of the vehicle drops by around 25%. (I checked this later, and found the Tesla owner forums are awash with discussions that absolutely back this up.)

Of course processors are constantly getting more efficient, and system designers will find things to optimise, but the scale of energy use would appear to be too big to ignore. This may be yet another argument for the real benefits to autonomous vehicles being found around level 4 (where sensing and ‘thinking’ can be streamlined to particular use cases) rather than level 5, where the AI needed to handle all those open-ended situations may need so much power that it destroys the business case.



Tiny data centre used to heat public swimming pool:


Could vehicle automation make carbon dioxide emissions and air quality worse?


Is it time to be more radical in rethinking rural buses?

I think the time is ripe for a really radical re-think of the way rural bus services operate, because of two new bits of technology that could be real game-changers. Let me set the scene first…

It’s not saying anything new or controversial to suggest that bus services in many rural areas are in a spiral of decline. Falling passenger numbers mean less revenue for the bus company, they cut back on the number of services, which makes the bus less attractive, passenger numbers fall further, and before long buses aren’t viable at all. The last service near me disappeared during Covid, never to return.

Of course with concerted effort some places are bucking the trend, and creating a virtuous spiral of increasing passenger numbers leading to improved services. A really good partnership between the local authority and the bus company is vital. Together they can put in bus priority measures at junctions so the bus is quicker than the car, provide attractive bus stops, offer integrated (often subsidised) fares, and invest in clean modern buses with wifi and phone charging. Doing all of these things, plus maybe using increased parking charges to subsidise buses, and setting up car clubs so more people can ditch a car altogether, can turn things around, and has in a few places.

But what if that’s just not enough? I’ve long had an idea for a more fundamental change, and a couple of things have come along that I think make it more likely to work – and definitely worth trying out as an experiment somewhere.

So, here’s my idea. Rural bus routes tend to go, literally, round the houses in order to serve multiple villages, feeding into the local town. This means they are much slower than driving, and infrequent (you’re lucky if a rural bus comes once per hour). What if, instead, the bus followed the main roads, bypassing the villages, allowing the same number of vehicles to deliver two or three services per hour, and completing the journey in a similar time to driving? Wouldn’t that be more likely to attract new passengers?

Well, yes, except how does anyone actually access the service? I have had this idea for many years now, and in the past I always thought it would be nice if people could access express buses like this by cycling to the bus stop – which works for me because I’m a keen cyclist. In fact, when I lived in Oxford this is what I would often do – express coaches go from Oxford to London several times per hour, and I would cycle to a coach stop and hop on (it was even possible to take my bike on the coach if I wanted). But as a wider solution it would clearly exclude the many people unwilling, or unable, to cycle to a bus stop.

So what’s changed? E-mobility, and apps, two things everyone is crazy about right now.

E-mobility puts the trip to the bus stop in everyone’s reach. Put a docking station for e-bikes and e-scooters in the centre of every village, with a quality, paved, off-road mixed-use path running out to the express bus-stop. At the bus stop itself, quality cycle parking, another docking station, and a drop-off area of car parking too (as a parent I’d rather drive my kids to a bus stop than the whole journey). And of course, an electronic sign giving a real-time readout of when the next bus will arrive.

The final piece of the puzzle, a travel planning app that can actually cope with multi-modal journeys. I use Google maps all the time – its cycling directions have got really good, and its public transport directions combine bus, train and walking perfectly. But it still can’t cope with the idea that I could cycle to a station or bus stop, often cutting journey time significantly. Create an app that lets you tell it you’re willing to cycle, or scoot, a certain distance to a bus stop, either on your own bike/scooter or hiring. Better still work with google to integrate this capability into their directions. And if possible include the ability to pay for the whole journey right inside the app, and just tap your phone at the docking stations and as you get on the bus. Please do let me know your thoughts in the comments, I love this idea but I’m not in the bus industry so I realise I may be naively missing something. And if you are in the business of planning bus services, and you want to give this a try somewhere, or you know of somewhere it has been

Are the best transport policies not about transport at all?

It’s been a week since I attended the excellent Zemo annual conference, and the thing that I’ve been thinking about most as a result is travel demand management (TDM). Chris Stark, CEO of the Committee on Climate Change, delivered a really great overview as ever, and he particularly drew attention to the purple wedge at the top of this graph – the bit about ‘reducing demand’. He understandably expressed concern that the government, and the wider transport professional community, is making a lot of noise about things like EVs, but reducing vehicle miles gets very little attention.

CCC balanced pathway for transport emissions

These concerns were echoed earlier this year when the RAC Foundation did some research into whether we could reach our transport emissions targets without reducing vehicle miles travelled. Their conclusion (I’m paraphrasing) – in theory ‘yes’, in practice ‘no’.

I should quickly point out that there are some subtle differences in what is meant by TDM in different contexts. In the RAC Foundation research, the focus is on reducing the number of miles travelled by cars. However, that could be achieved in four different ways:

  1. Making the same trips, but switching some of them to other modes (e.g. rail, bicycle)
  2. Making the same trips, but making them shorter (e.g. shopping closer to home)
  3. Combining trips so fewer are made (e.g. shopping on the way home from work)
  4. Eliminating trips altogether (e.g. working from home)

The thing that’s interesting about that list is that as you progress from 1 to 4, it gets less and less about ‘transport’ per se, and more about just how we live our lives. Transport planners think a lot about modal shift, and if they build good relationships with land use planners then they think about co-locating housing, schools, healthcare and shops to reduce trip length. (And if trips are shorter, it’s easier to achieve modal shift.) However, to my mind TDM in its purest sense is really about the second half of that list, the things that eliminate trips either by combining them or making them unnecessary.

So – to finally come back to my headline, maybe the best transport policies are the ones that eliminate or combine trips, and they often aren’t ‘transport’ policies at all. Covid has put working from home firmly on the agenda, but I can think of several other examples, such as:

  • The NHS rolling out technology that allows sufferers of chronic conditions to manage their health at home rather than making frequent hospital visits
  • Schools carrying out parent-teacher consultations online
  • Employers offering more flexible hours so that employees can attend appointments, shop etc. near their workplace during the working day
  • Rural post offices offering a wider range of services

Personally, I think the takeaway from Chris Stark’s presentation is that a dose of holistic thinking is long overdue here. Transport planners at all levels of government need to be talking to other departments to make these policy links more explicit, maybe even to fund them. A case could be made that we should take money from the roads budget and use it to finance national broadband rollout instead. We should definitely be delivering active travel policy through a pooling of resources for public health and transport. I’m quite sure that in many, probably most, cases policies to reduce travel overall will save time and money for both individuals and the public purse.

For those of us who work in transport, and the politicians tasked with deciding on policy, it’s easy to forget (or choose to ignore) that transport is mostly a means to an end, rather than an end in itself. Given the choice, most people would enjoy a pleasant walk to their local high street via a park or café, but would happily avoid having to drive in rush hour because that’s the only way they can pick up a prescription. Mobility should exist in service of quality of life, not to its detriment.


RAC Foundation research

Flower power – roadside verges could be a win-win

I’m inspired to write this post by the fact that I’m lucky enough to have an office window overlooking my garden. We mainly manage it for wildlife, and at this time of year it’s a riot of growth and colour.

Wildflowers at the roadside with Anaerobic Digester in the background

There are plenty of people who seem eager to paint renewables as a threat to other land uses – witness the Tories recent attack on solar farms as competing with farmland. (This despite the fact that they take up less land in the UK than golf courses.) If you’re prepared to look properly, there are plenty of creative examples of renewables and biodiversity, going hand-in-hand. Managed grazing under solar panels, protected marine areas around offshore windfarms – and the subject of this post, roadside verges managed for wildflowers… and gas.

There are 270,000 km of rural roads and motorways in the UK, most of which have roadside verges. The typical management regime is to cut them 2-3 times per year, and leave the clippings in situ, but this does little for biodiversity. Instead, they could be managed in the same way as a traditional wildflower meadow (like my back garden), encouraging more diverse plants, and the birds, insects and mammals that would follow. In effect we could have 270,000 km of much needed wildlife corridors connecting every nature reserve in the UK.

So what does the alternative management look like, and why don’t we do it? Well, we’d actually need to cut less often (twice per year), which would save money. But, we’d also need to collect the clippings, and that’s the problem. Collecting the clippings is essential, because diverse meadow needs poorly fertilised soil, otherwise it gets dominated by a few aggressive species like nettles and certain grasses. However, collecting the clippings needs specialist equipment that costs a lot more than a tractor and flail. Local/highway authorities generally can’t afford that extra expense.

So, could those clippings have a value that would effectively pay for collection? Well, as with any meadow, they can be turned into bales of silage and kept for months, but the roadside contamination (soot, tyre dust etc.) means that silage can’t be fed to animals. However, it turns out that it’s still excellent feedstock for an anaerobic digester – so it can readily be turned into renewable methane.

Lincolnshire County Council carried out a pilot a few years ago, which was written up by researchers from the University of Leeds and published in May 2020. Their headline finding was that silage from roadside verge clippings was a viable feedstock for anaerobic digesters, and that AD operators would pay enough for it to cover the cost of collection. So there you have it, a win-win, a nationwide network of biodiversity corridors and a huge new source of renewable gas all in one.

All of which only begs the question as to why we’re not seeing more verges managed in this way, three years on from that research? I suspect it’s partly reluctance to perceived ‘untidiness’, but piles of rough cut grass look pretty unsightly too, and I think once people see verges covered in a rich carpet of colour they’ll think differently (and maybe even drop less litter). Mostly I expect it’s a lack of capacity to change – local authorities don’t have the resource to try many new things, especially if it involves investing in new equipment.

But I think the more people know about this particular win-win scenario, the more wildflowers we’ll see – so share this post!

Reference: https://eprints.whiterose.ac.uk/160532/

Will electrification leave rural and small bus/coach operators behind?

It’s fair to say that city bus operators are leading the way in the UK (and elsewhere) in terms of vehicle electrification. It’s easy to see why – buses are providing a visible public service, and public opinion is firmly demanding cleaner air.

Plus, it’s always been the case that the newest buses are used first in cities, with older vehicles moved out to a second (and third, and fourth) life in more rural areas. This makes sense because city buses are used more intensively, so newer vehicles are preferred. It’s especially true for electric buses because (a) their higher capital cost can be more quickly recouped from their lower running cost, and (b) they save even more money where more polluting vehicles are subject to Low Emission Zone charges.

Bus in a field of wheat

There’s a similar picture with coaches. Large operators buy new vehicles to run the high mileage, profitable inter-city routes, while small operators, with only a handful of vehicles, are using coaches that are 10 or 15 years old to do school runs and day trips in villages and market towns.

So, will rural areas just have to wait for cleaner vehicles, and can we assume that as the current crop of electric buses (and a few coaches) will filter through the market over the next decade?

Well, maybe, but maybe not, and that has got smaller operators worried. At the excellent Zemo electric bus event with Abellio in London last week, I was chatting with Peter Bradley of the UK Coach Operators’ Association (UKCOA). We’d spent the morning hearing about the huge investments going into charging infrastructure for electric buses in London depots – very inspiring, but even if UKCOA members are able to buy a used electric coach in a few years’ time, how are they going to afford the infrastructure to charge it?

A couple of positive thoughts on this came out of the event. I chatted to Lucy Parkin of Kleanbus, who are taking old Optare Solo buses and repowering them with an electric drivetrain. Equipmake have just started to do the same for coaches. At the start of the electrification journey, taking an old vehicle and fitting it with an electric drivetrain was the only way to get electric versions of heavy vehicles. Once new electric trucks and buses started rolling off production lines, repowering was perhaps seen as a bit ‘Heath Robinson’, but now it’s having a resurgence in sectors where vehicles have a long life.

A burgeoning repower market may provide smaller/rural operators with a way to buy cheaper electric vehicles without waiting decades, but what about charging infrastructure? That’s going to be a tough nut to crack, and something rural councils need to address in their charging strategies. But one possible piece of the puzzle came out of chatting to Jon Eardley of Abellio. His depots are investing in dozens of high power chargers that buses will use overnight, but their depots are all but empty during the day. They are already in discussion with coach operators bringing day-trippers into London to offer their depots as parking locations, and potentially charging locations, during the day.