Isha's Taxis is located in the southwestern area of the map, south of Derwent Water. The first chapter is called "To the Festival." After a short intro, you'll be told to drive to the pickup spot. You have to get there within the time limit, otherwise you will fail. The time stops when you park.
After picking up the passenger, you'll be told to drive to the nearby festival site. You can get any number of stars on this chapter to be awarded the achievement. 3 stars for 1:15, 2 stars for 2 stars for 1:25, and 1 star for 1:45. Anything slower will fail the chapter.