My Thai bf, his Papa and I spent 4 nights in Chiang Mai.
During the visit, I enjoyed several opportunities to relax while Bf and Papa visited the many Temples and night markets.
I discovered that the Grab taxi fares were cheap...usually quoted 56-66-88 Thai baht for taxi...as compared to the Grab Taxi fares of 200-330 Thai baht in Pattaya.
Just download the Grab Taxi App...
No prepay ...just pay the driver.
The cars were newer and very good drivers.
BTW...we all had a great time