Yonah Freemark just launched the biggest expansion of transit network mapping on Transit Explorer and I built a new feature for TE that allows users to visualize the size of a network by decade from 1970 to today.

When looking at a region of the world, change the era of transit network that you’re seeing by selecting a decade from the dropdown menu under the “Change the era” heading. In a moment, the map will automatically refresh.

I’ll show you three cities:

  • Salt Lake City
  • Hong Kong
  • São Paulo

Salt Lake City

The Utah Transit Authority opened its first modern light rail line in 1999 from Salt Lake City to the southern suburb of Sandy. It opened the second line, from downtown Salt Lake City to the University of Utah, in 2001, in time for the 2002 Winter Olympics. Some games and ceremonies were held at the university. FrontRunner commuter rail opened in 2008, and the third light rail line, to the airport, opened in 2011 and various line extensions opened in 2013. A BRT route that opened in 2018 in Provo is also mapped but not shown while a BRT route in Salt Lake City is shown under construction in 2024.

View Salt Lake City on Transit Explorer

Hong Kong

In 1970, the only rail transit that Hong Kong had were a tramway on Hong Kong Island and the East Rail Line, which opened in 1910 and was electrified in 1983. Every decade since there was a new line or two on the Hong Kong MTR network, culminating in the ten lines you see in 2024.

View Hong Kong on Transit Explorer

São Paulo

In 1970, São Paulo’s metropolitan network, Metrô, didn’t exist, but it had six regional train lines operated by three railroads – these kinds of trains are shown in brown on Transit Explorer. The metro, shown in blue, began in 1974, and now has six lines (including one monorail line) while the regional train network was modified to five lines. São Paulo saw its first bus rapid transit (BRT) line added in 1988, but added four more BRT lines since then – just five of the over 900 bus routes operated by EMTU.

View São Paulo on Transit Explorer