Stephanie Lay is a post-graduate psychology researcher at the Open University. She doesn’t drive but has had the pleasure of being a passenger in the Magic Flying Leaf for the last three years. She works full-time for the Open University and studies part-time working on a thesis about the uncanny valley phenomenon: she spends most of her free time studying near-human faces and researching why they can be unsettling and creepy. Her research page can be found at the Uncanny Valley Open University site. She gives us a psychological look at range anxiety. She has already talked about her personal experiences and the human factor now she looks at the car’s role.
So far, I’ve looked at the driver’s role in range-anxious journeys: this section will consider the role of the EV itself. Firstly, it’s important to consider range anxiety in terms of how far people really need to travel. If most typical journeys could be made without exceeding the comfortable range, anxiety should be minimal.
EVs display a measure of ‘distance to empty’ (DTE) showing an estimate how how far you will be able to travel before needing to re-charge. As a population in the UK, our average driving distance is quite low: according to the 2012 National Travel Survey looking at average journey distances in Great Britain, the average journey is 7 miles.
A cross-EU survey carried out in 2011 by Ingo Bunzeck, C.F.J. Feenstra, and Mia Paukovic found that 40% of UK respondents had a daily travel need under 12 miles, the smallest average reported in the survey. EVs currently on sale in the UK have ranges roughly in the region of 80-125 miles so theoretically we should only be anxious on a tiny fraction of our journeys.
However, estimates of range requirements are based on a higher expectation of what we would like the car to be able to do, rather than what is actually needed for our everyday journeys. A study by Ona Egbue and Suzanna Long in 2012 surveyed people on their actual regular journeys, and compared this to the range they would like in an EV. At the time of the survey, the average journey for those participants would have been 36 miles according to the local National Household Survey. As the table below shows, hardly any participants cited this as their desired range, and the majority had a desired range greatly in exceed of their day to day needs regardless of their actual driving patterns.
This might seem like an obvious conclusion: when asked how much range they want, people are likely to want more regardless of need! Cars have been symbolic of freedom for several generations, and putting limits on that freedom seems bound to feel constraining.
At the moment range appears to be increasing by small increments and it will probably be several years before there is an affordable EV with a range that can match an ICE vehicle and/or live up to people’s desired ranges. In the meantime, tools that help EVs to communicate with their drivers and give them detailed information about how their current driving affects the range they can achieve are crucial.
This is especially the case when comparing the range of your new EV to the old internal combustion engines you were used to: no matter whether you only need to go a handful of miles, a ‘tank’ of even 125 miles feels small if you are used to a conventional range of 300 miles or more. According to Tomas Franke’s 2011 study, one way to help with range anxiety would be to provide more information along with the raw estimate of the distance to empty.
For example, some indication of confidence levels in how the remaining range had been calculated would help drivers to understand whether that was being calculated based on the last few seconds of driving behaviour, or whether a longer-term measurement was being used to calculate it. Their study found that reducing ambiguity while increasing the driver’s sense of control over the situation was key to helping them make the most of their available range. Similarly, being able to select route finding options for most efficient routes as well as shortest or fastest routes would allow drivers to feel more in control of their driving, shifting the locus of control back to the driver and thus diminishing the anxiety.
Adding information to augment understanding is laudable but can be hard to achieve practically in car designs. Given that these are systems designed for use in motion, drivers will only be able to look at in-car displays very briefly. If those displays present more information, there is the risk that they may be harder to comprehend in those at-a-glance moments, and may actually cause distraction or confusion.
There is a rich and detailed literature in cognitive psychology that deals with attention and how certain cues may actually distract from the task at hand rather than providing a supplementary service. (Size, colour and movement are particularly salient for visual displays, with volume and repetition significant for audio cues.) To date, there has been no applied cognitive psychology research into the interfaces that might help EV drivers make the most of their available range, but this would be a fruitful area for future research.
The picture for individual drivers is made more complex as many systems for estimating DTE are highly proprietary. Changing to an EV from a different manufacturer may require accommodating a new type of interface and learning how the DTE estimates are calculated. It could be argued that more standardisation is required across the industry: but then, would some manufacturers experience a loss of competitive advantage?
Finally, a last area to consider is the issue of range anxiety as function of how long a driver has had an EV. In many ways, range anxiety could be predominantly a new user phenomenon: Franke’s work suggests that learning about your car’s limitations will certainly help to alleviate any anxiety. His team found that as drivers understood more about how the range estimates provided by their vehicle were calculated, they began to feel more comfortable with the vehicle, and decrease the safety buffer limiting their comfortable range.
Knowledge and experience are key to efficient range utilisation and the avoidance of anxiety, and it may be that some common techniques can be suggested by vehicle manufacturers as a way for new drivers to make the most of their comfortable range quickly. Based on the observations made by Franke’s team, new EV buyers should be encouraged to keep a diary of their actual driving behaviour between ordering their new EV and taking receipt.
Having a concrete document showing what their real-world requirements were before moving to an EV may help them adjust their requirements downward, and be more comfortable with their EV when it arrives. While experience may well help in alleviating that anxiety experienced because of unfamiliarity, we may find that there is a U-shaped curve in anxiety: an initial highly anxious period while adjusting to the limitations of an EV is followed by a less anxious spell helped by understanding those limitations, which then eventually culminates in another anxious period when battery depreciation means that familiar journey are no longer as easy or even possible.
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