Human drivers do not yet know enough about autonomous vehicles to take advantage of them, according to new research from the Transport Research Laboratory (TRL).
The study, conducted by TRL as part of the GATEway driverless car project in Greenwich*, investigated how drivers might adapt their behaviour in the presence of autonomous vehicles.
Among the key findings is that the majority of motorists did not change their driving behaviour and continued to make decisions about overtaking or pulling out into traffic, based on their judgements of safety.
Nick Reed from TRL said the findings suggest at present drivers will treat autonomous cars ‘as they would any other vehicle’.
The trial took place in TRL’s DigiCar driving simulator and sought to explore how drivers will respond to automated vehicles in an urban environment.
Participants completed a series of short simulator driving scenarios, including overtaking and junctions, within a 3D virtual replica of the Greenwich Peninsula. The proportion of automated vehicles in traffic was varied to represent the transitional phase between a fully and partially automated vehicle fleet.
While overall findings suggest driver behaviour will remain largely unchanged in the presence of autonomous vehicles, there was ‘tentative evidence’ that some drivers may adapt their driving behaviour as autonomous vehicles become more prevalent.
For example, drivers pulled into smaller gaps between vehicles at junctions when there were more automated vehicles in the traffic, but did not necessarily intercept automated vehicles more readily than conventional vehicles.
Professor Nick Reed, academy director of TRL, said: “As automation becomes more prominent in vehicles, we are likely to see a mixed fleet of non-automated, partially automated, highly automated and (eventually) fully automated vehicles for many years to come.
“Through that transition period, human drivers and other road users will be encountering autonomous vehicles in increasing numbers. The way in which human driven and automated vehicles interact will have major impacts on traffic flow dynamics and road safety.
“What we have found suggests that people find it hard to recognise automated vehicles and/or don’t yet understand how automated vehicles behave.
“In terms of their driving behaviour, they therefore treat them as they would any other vehicle. It is possible that this could change as exposure to autonomous vehicles increases, but more evidence is needed to substantiate this.
“A small number of participants did pull out into smaller gaps when there were more automated vehicles in the traffic.
“This could be due to an increase in confidence about pulling out in front of an automated vehicle, with some participants citing this as a reason. We would be interested in understanding why these drivers took this approach and how these behaviours evolve over time.”
*The GATEway project, located at the UK Smart Mobility Living Lab in Greenwich, is an £8m research initiative created in 2016 to investigate the use, perception and acceptance of autonomous vehicles in the UK.
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