@Disrupted
Taxi fares are made to get a lot of profit out of relatively short distances. From 5 minutes of google research I found the standardized price per mile being about as much as the price of a gallon of gas. To the driver, this night has been as if he had a constant stream of rides, which is unusual and means he'd make a ton of money. Even at his discount price he probably would have made a pretty penny, so paying him full price is already a big tip.