Research: USA & Europe’s best subway systems

May 16, 2022

All over the world, people use subway systems every day, every hour, every minute, you get it. We take them for granted but we should be celebrating these feats of engineering - rivets to beams and tracks to wheels.

We’ve looked at some of Europe and the USA’s most impressive subway systems and ranked the following data points based on performance: air quality, cleanliness, ratings, track length, stations and length to station ratio.

The data suggests that Boston has the very best subway system in the USA and Europe with top-7 ranks in cleanliness and air quality. The Boston subway system also has the very best station v length ratio with 14 stations per 10km of track.

Oslo, Norway; London, England; and Berlin, Germany make up the top four in the study with the former having the cleanest air whilst underground and the latter providing Germans with some of the longest track and most stations.

Subway’s thrum with life and energy, they are the veins that connect to the beating heart of a city. Not only are they the most efficient, cheapest and most environmentally friendly way to get around, but subways are also often the best way to get a real glimpse into a city’s culture, personality and people.


  • Air Quality: Was collected from IQAIR and looks at the average air quality including PM2.5, PM10 and more.
  • Waste Management Index: This is a combination of food waste, population and waste management efficiency.
  • Excellent Reviews: The percentage of all reviews which were Excellent, thanks to Tripadvisor
  • Track Length: Data was collected from
  • Number of Stations: Data was collected from
  • Length v Station Ratio: A final index calculated by figuring the number of stations per 10km of track.

Overall: Once all data points were collected a scoring metric was put together to rank the cities in the data.