On any given city street, only a portion of the vehicles are private passenger cars.
Taxis make up a large part of the traffic in cities, and in the same way it's proved popular with individual owners, the Nissan Leaf electric car appears to have the favor of cabbies.
The Leaf--along with the e-NV200 electric van--is becoming more common in taxi fleets, although not yet in the United States.
Nissan says there are now more than 550 of its electric cars operating as taxis in Europe.
That includes more than 100 vehicles delivered in 2015 alone.
Of that total, 65 taxis went to the Green Lite Taxi service in Budapest, leading Nissan to believe that electric-taxi demand will expand further into Eastern Europe.
Nissan e-NV200 taxis in Barcelona
Nissan also plans to deliver eight electric taxis to a company in Vilnius, Lithuania, before the end of the year.
So far, The Netherlands has the largest fleet of Nissan electric taxis, with 94 Leaf and 167 e-NV200 cabs operating there.
Amsterdam's Taxi Electric launched a fleet of 100 Nissan Leaf taxis in 2011, and has since augmented it with some Tesla Model S sedans.
ALSO SEE: NYC Officially Launches Nissan Leaf Electric Taxi Program (Apr 2013)
The U.K. has the second-largest fleet of Nissan electric taxis with 134, followed by Estonia, Hungary, and Germany.
Using electric cars as taxis not only cuts emissions from vehicles that spend lots of time on the road, it also helps prove the durability of battery powertrains.
Map of Nissan Leaf electric cars used as taxis in Europe, Nov 2015
Nissan claims one Leaf taxi operating in Estonia has racked up 218,000 kilometers (135,458 miles) on its original battery pack.
While Nissan has demonstrated Leaf taxis in the U.S., there has been no large-scale attempt to deploy them here.
The internal-combustion version of the e-NV200--the plain old NV200--is New York City's newly-standardized "Taxi of Tomorrow."
That at least leaves the possibility of future electrification of the city's taxi fleet, something that was studied by the administration of previous mayor Michael Bloomberg.
2013 Nissan Leaf electric car tested as taxi in New York City, April 2013
But even if it doesn't win over U.S. taxi operators, Nissan can at least be content with the Leaf hatchback's popularity among non-commercial buyers.
With more than 195,000 sold worldwide, the Leaf is the best-selling electric car in history.