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Ride share service vehicles at the pickup area at Los Angeles International Airport

The explosive growth of ride-sharing has intensified US traffic congestion (such as at Los Angeles International Airport in California, shown above). Credit: Patrick T. Fallon/Bloomberg/Getty

Environmental sciences

Uber and Lyft drive US gridlock — but not cuts in car ownership

In the United States, ride-share services lure passengers away from public transit instead of luring drivers into giving up their private vehicles.

The rise of ride-sharing services has reduced US public-transportation usage and worsened traffic jams in US cities.

Ride-sharing giants Uber and Lyft began operating in the United States in 2010 and 2012, respectively, and promote this form of travel as a sustainable way to increase urban mobility. To quantify the services’ effects, Jinhua Zhao at the Massachusetts Institute of Technology in Cambridge and his colleagues analysed transport data from across the country.

The authors found that ride-sharing services had almost no effect on private car ownership but reduced public-transport ridership by almost 9%. Traffic jams also became longer and slightly more intense in cities where car-sharing services were available.

Well-organized ride-sharing does hold potential to improve mobility, the researchers note. But the road to sustainable urban transport will be even rockier because of the COVID-19 pandemic, which put an end to pooled car-sharing services.

More Research Highlights...

Plastic and other debris floats underwater in blue water

Plastic detritus from snacks and meals floats in the Red Sea. Marine sampling shows that food waste accounts for nearly 90% of plastic pollution at some locales. Credit: Andrey Nekrasov/Barcroft Media/Getty

Ocean sciences

Humanity’s fast-food habit is filling the ocean with plastic

Food bags, drink bottles and similar items account for the biggest share of plastic waste near the shore.
Conceptual artwork of a pair of entangled quantum particles.

An artist’s impression of ‘entangled’ particles, which share properties even at a distance. Entangled photons can be used to help secure a multi-party video meeting. Credit: Mark Garlick/Science Photo Library

Quantum information

Quantum keys dial up tamper-proof conference calls

A new experiment efficiently distributes the highly secure keys to four parties instead of the typical two.
Farmers harvest pineapples in a field.

Workers harvest pineapples in Lingao County, China. Less than one-third of the money spent on food eaten at home reaches farmers. Credit: Yuan Chen/VCG/Getty


Poor harvest: farmers earn a pitiful fraction of the money spent on food

The bulk of consumer food spending around the world ends up in the coffers of distributors, processors and other parties beyond the farm gate.
A woman wearing a protective face mask splashes her hands in a jet of water

A pedestrian seeks relief from searing temperatures in Spain, where a high proportion of heat-related deaths have been linked to climate change. Credit: SALAS/EPA-EFE/Shutterstock

Climate change

More than one-third of heat deaths blamed on climate change

Warming resulting from human activities accounts for a high percentage of heat-related deaths, especially in southern Asia and South America.
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