In an analysis of car-sharing programs across five cities, a UC Berkeley study showed a significant relationship between the number of available shared vehicles, and the number of vehicles sold by members of that network.
Across the five cities that took part, the study found that members of the network sold between 1 to 3 vehicles for every car share vehicle available, 74% of which were over ten years old — a significant reduction in vehicles with specifically outdated emissions systems. And if we want to dig into those emission impacts even further, we find an average 10% drop in GHG emissions across the population using the car-sharing service. People using car-sharing services were demonstrably buying less new vehicles, selling old vehicles they didn’t need, and reducing their overall emissions.
And what about that opening question — how does buying a bunch of cars get a bunch of cars off the road? The studies showed that if you take vehicles sold, combined with new vehicles never purchased (based on historical trends), all in, each car-sharing vehicle replaced between 7 to 11 privately owned vehicles.