Driverless cars and the future of public transport

To round off this little series on driverless vehicles I will touch on a matter that has garnered much comment in many media outlets – how they will impact on public transport. Many commentators have – often gleefully – posted on how driverless cars will render the likes of HS2 obsolete (step forward Allister Heath as the most notable example of this). This is a very bold prediction, and sadly for many commentators shows a basic lack of understanding of how public transport actually works.

There are many types of travel by public transport, so let’s start on the home turf of HS2 critics – intercity travel. The Demand for Public Transport: A Practical Guide reveals cross-elasiticities of demand between car travel and intercity public transport travel is relatively inelastic in respect to both time and costs. Evidence from Ireland reveals a key determinant of intercity mode choice is travel time, confirmed in Dutch research which also stresses the roles of socio-economic characteristics in mode choice and trip purpose.

That sounds like a load of technical gobbledegook, so let me translate. For intercity travel, travel time is of paramount importance. This is reflected in the National Travel Survey, where for trips of over 50 miles rail accounts for a much higher proportion of travel, certainly compared to overall trips – though the car is still the dominant mode.


When it comes to long distance, speed is everything

This is an important finding. How much impact can driverless cars make on trips where cars are already overwhelmingly dominant and walking and cycling are not an option? To make inroads into the public transport long distance market, driverless cars will have to make significant time savings on city centre to city centre journey times. Unless urban speed limits are substantially changed and congestion truly becomes a thing of the pass, the ability of them to save travel time is negligible.

No doubt you are thinking – ahh, but what about driverless cars allowing us to make better use of travel time, James my boy? Well, I did cover this in the first post of this series, and it is likely that people will use such travel time in ways that benefit them. Taking the logic of the point you are making, most people would choose slower journeys to make the best use of their travel time. This is contrary to research in public transport that shows travel time as a strong determinant of demand, particularly on long distance trips. People still make best use of that travel time, but not at the expense of speed.

Looking within our cities, a key factor will be how driverless cars will change car ownership patterns. Data from the National Travel Survey shows the key determinant of bus use being ownership of a car, so if driverless vehicles facilitate a further jump in car ownership – particularly through shared ownership – bus use should decline according to current knowledge. The best evidence that we have of this currently is evidence on car clubs. This proudly states that users of car clubs are more likely to use public transport, but critically shows no evidence that this is an impact of being in a car club.

Car Club Car

This all assumes that shared ownership also overcomes current barriers to car ownership. Finance is the obvious one, with the well-established trend of car ownership increasing with income. In the developed world declining car ownership among young people is especially pronounced, being attributed to cost, use of the internet, thinking multi-modal green attitudes to name but a few.

Continuing the divergence further, it will also be interesting to see if driverless vehicles change attitudes to car ownership more generally. The car industry is bullish that it will not, and to be fair there is some research with car use seen as a normal part of adult life by older children and as an indicator of social status. But assuming trends currently being seen in young adults continue, smarter ownership models are certainly a possibility for many. I have yet to see the research to indicate that this would be widespread, but the success of car clubs in cities is a useful indicator.

It is my view that in this regard, driverless cars will not fundamentally change our attitudes to car use and ownership, at least not initially. Those with a preference towards car use will still use cars, those who prefer a choice will still exercise that choice. I admit this is not backed by research, more a feeling.

Anyway, I digressed slightly. What will be interesting in the urban context is the need for space efficiency. In purely highway terms, driverless cars show no evidence yet of being more space efficient outside of closer vehicle spacing that we have discussed. In fact, in some of the ideas mooted for driverless vehicles where some may use the highway network without drivers, such vehicles will be less space efficient than current vehicles.

Comparing bus, cars, and bikes
Space efficiency, transport style

This is where urban public transport will still play a role, by efficiently transporting large numbers of people around our cities. Even assuming full occupancy of driverless vehicles, public transport can do more (and cycling even more) in the same space. So long as we want it to be like that.

Current arguments against public transport also assume that public transport itself will not benefit from driverless technology. Experience in rail – notably the Paris Metro – shows that such technology can reduce headways, boost frequencies and reliability, and subsequently patronage. Guided busways like those in Cambridge and in Luton are a more primitive example – again significantly improving frequencies. Even if half the predictions for driverless cars are proven true then buses can also benefit from such technology.

It also assumes that public transport will not continue to compete against driverless cars by providing seamless journeys and improving its own offer. Integrated ticketing, improving service frequency and reliability, prioritisation of public transport in general traffic, and improving the on-vehicle offer such as free wifi and comfortable seating are just a few examples of how patronage can be boosted and the role of public transport can be maintained. When delivered as a package, the research shows that these can have significant impacts on boosting patronage.

I have yet to see anything convincing by way of research that shows that public transport’s time is numbered in a future of driverless cars. This may turn out to be true of course, as we have no idea of the policy decisions and societal attitudes that will shape the fortunes of all modes of transport over the next 10, 20, 30 years or so. But making the likes of HS2 a white elephant? Show me the evidence please.

Which leads me onto a question that I have been meaning to pose to the proponents of driverless cars. Is their purpose simply consolidate a current dominant market position in personal, or to expand the market? And if so, to where? There are known limits on personal travel and travel by car, and peak car is an increasingly-accepted theory. So why should driverless vehicles be radically different?

For us professionals, it also does not alter the fundamental question that we need to ask ourselves: what sort of towns and cities do we want to create? If we wish to continue on the current path, we just focus on getting as many driverless vehicles through our highway networks as we can. But if we want to create livable cities, we question their impacts, and use them and direct them in a way to create them. And based upon what we know, we can do this.


2 thoughts on “Driverless cars and the future of public transport

  1. Philip

    Driverless cars will exist in a variety of business models, as one link in your previous posts described. I guess (like our Australian friend above, without evidence) something like the following.
    (a) Ownership model (with families wanting to own one large family car for status and familiarity reasons).
    (b) Shared ownership/car rental model.
    (c) Taxi model.
    (d) Shared taxi model.
    These four models blur into each other, and (d) could well blur into public transport – imagine using a smartphone app to book a cab, which offers you the opportunity for a cheaper journey cost for minor diversions and stop-offs to pick or drop off other people: it starts to look very much like a bus. While very highly used point-to-point services (such as HS2) would still be in demand, the existing shape of bus services would be challenged. In rural areas, such a service would likely finally kill off local buses, and in denser urban areas could change the shape of bus services from static ‘route number’ based services towards dynamic services that don’t require passengers to change buses.
    There’s a challenge for policymakers which is both economic (a mechanism for subsidies for bus services for pensioners etc against this background) and traffic rules based challenges. If a street is currently closed to motor traffic except buses and taxis, can it cope with dynamic buses or shared taxis? As the distinction between taxis, minicabs and rented cars vanishes, how many people need it contain before it becomes a bus and allowed to use the street?
    (Incidentally, my big hope for driverless cars in liveable cities is that we can finally put to rest the concept that being allowed to store as many cars as you like on the street is some sort of human right).


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s