Google Maps Directions (Routing), by Transit / Public Transport

Primary tabs

gdt
Examples: 
gdt brandenburger tor, potsdamer platz
Get a route Brandenburger Tor to Potsdamer Platz by public transport
URL: 
https://www.google.com/maps/dir/?api=1&origin={%start|type=city}&destination={%destination|type=city}&travelmode=transit