[2020] Trams gone since Sunset Harbour

The tram tab should be next to the trolleybuses - it's just been pushed over one space.

If you don't see it anywhere, try verifying game files and making sure the Snowfall DLC is enabled in your games library.

https://support.steampowered.com/kb_article.php?ref=2037-QEUH-3335

Trams are content only available in Snowfall, so if you don't have Snowfall, it makes sense that you don't have trams.