The impacts of automated driving of passenger cars were studied¹ in the EU Flagship project Hi-Drive, based on data simulations using data collected with real automated vehicles in real traffic on motorways, urban and rural areas, and on proving grounds.

According to the results, 20% of fatal accidents on motorways today would be avoided if 30% of passenger cars in the traffic flow were automated. In urban settings, the corresponding reduction in accidents would be 22%. The number of accidents with severe and slight injuries would decrease even more. However, the introduction of automated driving may lead to new types of accidents, resulting from situations where the automated vehicle cannot continue driving and needs to slow down or even stop before the human driver takes over control. The study estimated these to account for 0.3% on motorways at a 30% penetration rate.

Another minor negative impact would be an increase of 0–4% in travel times due to changes in target speed and rerouting. Moreover, automated driving is likely to increase travel quality and produce significant impacts on mobility. By enabling users to engage in non-driving-related activities, enhanced travel quality can lead to more frequent and longer trips.

“From a socio-economic perspective, the safety impact and increased travel comfort form the main monetary benefits,” says Satu Innamaa, Principal Scientist at VTT.

The project addressed EU-level impacts covering the entire traffic flow, i.e. automated and non-automated light and heavy vehicles, across all driving scenarios. The results on traffic efficiency and environment revealed that, with automated vehicles in the traffic flow, the average tractive energy use per vehicle-kilometre travelled decreases under most conditions. The impacts on CO₂ emissions at the network level were small (between –1% and 0%).

“While automated vehicles tend to be electric, the project was agnostic to the motor type. It was important to limit the scope of research strictly to the impact of the changes in driving behaviour caused by automation – and not to mix it with impact of the electrification of the fleet,” Innamaa explains.

Key impacts of automated driving (assuming a 30% adoption of passenger cars):

• Decrease of fatal accidents on motorways and in urban traffic
• Average travel-time increased for all vehicles in traffic
• Tractive energy use per vehicle-kilometre decreased
• Decrease in CO₂ emissions
• Enhanced travel comfort

Source: the original press release can be found here

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1. Led by VTT, responsible for the he project’s methodology and the impact assessments. Automated driving was assumed to be available on urban streets and motorways in good driving conditions – not yet everywhere or in all conditions. ↩︎