Dubai adds daily, weekly, monthly and yearly passes for metro/bus/water bus services! Daily passes cost 20 AED which is just over $5 USD. Kids under 5 ride for free. Single tickets can still be purchased at the following rates:
You will now need to be more aware of the number of zones you are traveling if buying weekly pass or single fare tickets.
T1- trip that starts and ends in the same zone
T2- trip that starts in one zone and ends in adjacent zone
T3-trip through more than two zones.
The weekly, monthly, 90 day and yearly passes all have different pricing depending on T1, T2 or T3. Thankfully the daily passes are the same 20aed price regardless on number of zones you will cross.