FLEET MANAGEMENT | DRIVER STRESS Is an electric van less stressful to drive? George Barrow goes back to back with a diesel van to test the science.
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ith a temporary shortage of fuel heightening the anxiety levels of combustion engine van drivers, you’d be forgiven for thinking that the woes of an electric driver pale into insignificance. After all, the useable range of an electric van is in some cases more than 200 miles, which, providing there’s regular opportunity to charge, is ample for the majority of use cases. Electric vehicle range anxiety should therefore be reducing for drivers and perhaps as a result the overall experience of driving an electric vehicle is also becoming less stressful. The big question though is whether an electric vehicle is less stressful to drive than its diesel equivalent, and will electric vans create a new breed of calmer, more relaxed van drivers? With no gear changes, less noise and fewer vibrations, it’s long been hypothesised that EVs deliver a more relaxing drive, but how exactly can you qualify the stress levels of driving an electric van compared to a diesel model?
Medical-grade monitor Using a medical-grade wearable monitor, VanUser took part in an experiment to determine the relative stress levels of driving an electric van, benchmarking it against a diesel equivalent in mid-morning London rush hour. By monitoring the biophysiological responses – that’s to say something akin to the blood, sweat and tears of the driver – a picture can be built up to show a driver’s reactions to the differing sounds of the diesel and electric vans. The vehicles in question were the new Fiat eDucato and the existing and soon to be updated diesel-powered Fiat Ducato. The device to measure the stress levels was a wristwatch-like gadget called an Empatica E4 that’s not too dissimilar to a wearable health monitor like a FitBit. It uses a photoplethysmography sensor to optically monitor heart rate, electrodermal activity, body temperature and muscle movement. The theory is that an increase in blood flow due to stresses will increase the recorded heart rate and body temperature, while the electrodermal activity measuring the moisture on the skin (i.e. sweat), will rise if the driving be30 VANUSER • OCTOBER 2021
comes more stressful. Taking matters a step further, an electroencephalograph (EEG) can be used to estimate metrics of brain activity, which can be correlated to show restful or active mental states, which combined with the photoplethysmography sensor can estimate the emotional state of the driver.
Stress survey In a nutshell, if all the vital signs are elevated, you’re pretty stressed out, and while it might not be solely to do with the acoustics of the vehicle – after all London traffic is renowned for being slightly challenging at times – higher levels across the range of the data, along with a short and snappy stress survey after each drive will help determine the outcome. It’s science then, but with a healthy margin of error, educated guessing and a lot of applied knowledge from psychoacoustic expert Duncan Williams, CTO of biometric and psychoacoustic consultancy firm WaveTrace. The route for this experiment was
STRESS through parts of London that will from October 25 fall within the recently expanded Ultra-Low Emissions Zone (ULEZ), making an electric van an ideal candidate for the job – despite still being a relative rarity even in this part of the city – while the diesel van will still be eligible for penalty-free admission by virtue of meeting the Euro6 emissions targets as well. Of course, it wouldn’t be a proper experiment with just one test subject, so a total of 12 people took part in the driver stress level comparison, all of whom had varying levels of experience in driving vans, driving in busy cities or neither. In my case, it was very much a question of knowing both vans and
