Trivia: You don't have to be a big The Big Bang Theory fan to know that Sheldon has his spot on the couch, but did you notice that other characters also sit in 90% of scenes on the one spot. Leonard is always on the sofa left to Sheldon, Penny is almost always on the sofa across Sheldon, Howard is always next to Sheldon on the couch (except in situations when Amy or Bernadette sit between him and Sheldon), and Raj is always on the left side of the couch (viewers' left), or on the floor.
Trivia: When ever the characters visit Will Wheaton's house, the number on the house is 1701, which is the hull number of the USS Enterprise from all the Star Trek TV shows and movies. Wheaton rose to fame as a cast member of Star Trek: The Next Generation.
Chosen answer: It does. The variable cleanliness of the cab and the habit of taxi drivers to engage customers in small talk would be too much for Sheldon to handle, and not an option for him.
Captain Defenestrator