What you're looking at is a map of Europe Union showing where the Joint Research Center (JRC) predicts that you'll find EVs in the EU in 2030.

According to the JRC Map, London Seems to be Tops in EV Density in 2030...Likely Largely Due to the City's Congestion Charge and Influx of Electric Taxis Like This One From Nissan

According to the JRC Map, London Seems to be Tops in EV Density in 2030...Likely Largely Due to the City's Congestion Charge and Influx of Electric Taxis Like This One From Nissan

The light gray areas will be the least EV dense.  The dark gray areas, the most EV dense.

The map displays city centers in a different way.  Though most EV dense cities are displayed in green.  The least EV dense cities, in orange-red.

As Daily Fusion reports:

"A study by the JRC, the EU in-house scientific service, identified the possible lead markets for electric vehicles and hydrogen fuel cell vehicles in the European Union."

JRC based its predictions on several studies it conducted.  Daily Fusion states the following:

"Those studies revealed that infrastructure availability, privileged access to dedicated lanes, parking facilities, adapted city centers, commuting behavior, the environmental footprint and fuel cost savings are important drivers. With the help of experts, these were analyzed at regional and city level in order to identify possible early-adopter markets for these innovative technologies."

The map above is the result of years of hundreds of hours of work put in by JRC.

Source: Daily Fusion