Here's a web service for Helsinki tram GPS data: http://transport.wspgroup.fi/hklkartta/
For some reason it's ridiculously hard to find as it's not linked to from the pages you usually use to find transportation.
For some reason it's ridiculously hard to find as it's not linked to from the pages you usually use to find transportation.
Some relevant public transportation data sources for Helsinki: http://www.hri.fi/en/data/hsl-reittiopas-api/