What is the cheapest way to travel daily in Riyadh?

The cheapest way is the Riyadh Metro and Riyadh Bus, run by the Riyadh Public Transport Authority. You pay with a Darb card or the Darb app. Fares are by time, not distance, and one ticket covers both metro and bus. A 2-hour ticket is SAR 4 in Regular class. A 3-day ticket is SAR 20, a 7-day ticket is SAR 40, and a 30-day ticket is SAR 140. For daily work travel, the 30-day ticket at SAR 140 is best value. Buy and top up on the Darb app or at station machines. The metro runs from early morning to midnight.