Instructions how to travel from O.R. Tambo Airport to Johannesburg Park Station like locals using Metrorail Gauteng. The whole trip takes about 1.5 hours, involves 15 minutes of walking and costs 8.5 ZAR per person (less than 1 dollar/euro). The fancier Gautrain is 19 times more expensive (162 ZAR).
Walking map to the closest local train station
Here is a walking map to the closest Metrorail station Isando:
Go to the ground floor of Domestic Terminal B. Walk all the way to the southern end of the terminal until you see a clinic. Go out and turn left. Keep walking on the left side and walk until you see a walking bridge that goes over the highway. Cross the bridge and the railway bridge, buy a ticket from the ticket counter and go to platform one to wait for your train. There are several trains. Take one that has a number starting with 06. The Metrorail train trip takes about 1 hour and the walk 15 minutes. Johannesburg Park Station is the last stop so you can't miss it.
Happy travels!