While some expect ride-hailing fleets to have less impact on the environment as they replace privately-owned cars, new research suggests that this might not actually be the case.

In a study into the emissions produced by ride-hailing fleets, researchers from Carnegie Mellon University simulated replacing private vehicle travel with ride-hailing services in six U.S. cities.

They found that because ride-hailing vehicles are generally newer, they emit less pollution during cold starts and this could trigger a 50 to 60 per cent decline in emissions. However, ride-hailing vehicles also use about 20 per cent more fuel and thus emit more greenhouse gas emissions because of the miles they are driven without paying customers.

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There are other downsides to large fleets of ride-hailing vehicles. For example, researchers concluded that overall costs associated with traffic congestion, crashes and noise increase by 60 per cent with ride-hailing vehicles and these costs become even more significant when ride-hailing is used instead of public transport, Auto News notes.

These study findings mimic those from MIT and Harvard researchers who found that even fleets of all-electric robotaxis could in some cases actually increase pollution.

Moreover, the impact of ride-hailing services on public transportation is particularly evident. A separate study from University of North Carolina and University of Michigan researchers states that ride-hailing fleets have “catalyzed a downward spiral in many public transportation systems.” The Covid-19 pandemic has furthered the negative impact on public transportation. Researchers say this is particularly concerning as it is the most vulnerable and disempowered in society that feel the brunt of these impacts.