Taxi Driver

Taxi Driver is a side mission in every Grand Theft Auto III era game, Grand Theft Auto IV, and Grand Theft Auto: Chinatown Wars that requires the player to drive passengers to specific locations within a time limit for a cash reward. In the Grand Theft Auto III era the side mission is triggered by entering a taxi and pressing the side mission button. In Grand Theft Auto IV the side mission is triggered by telephoning Roman about taking a fare.

Description
In the GTA III era games and GTA Chinatown Wars the player can earn money by delivering pedestrians to their predetermined destination within a time limit. Starting the mission lights up the taxi's roof-mounted taxi sign encouraging nearby pedestrians to flag the player's taxi down. Once a pedestrian enters the vehicle, the destination is displayed on screen and is marked by a blip on the radar and a colored marker at the destination itself. The allotted time given is calculated roughly from the distance to the destination, and an additional 30 seconds (10 seconds for other GTA III Era games) is granted upon completing a fare to find another one. If the player runs out of time, exits the vehicle or damages their vehicle too badly, the passenger will flee, ending the mission. From Grand Theft Auto: San Andreas and onwards the taxi side mission adds a "tip meter" which rewards players for delivering fares quickly and safely and punishes them for driving recklessly or taking too long.

In Grand Theft Auto IV the mission is no longer possible to complete in a normal taxi. Instead, Niko can perform the taxi side mission by phoning Roman Bellic for fares. Following the mission Jamaican Heat, Niko can call Roman to drive a fare; Roman will give the location of the customer and his/her destination as well as tell Niko to pick up a Taxi at the cab depot, if Niko is already driving one of Roman's Taxi, he would inform Roman that he is already driving in one and he would go straight to the customers. If the player completes 10 of Roman's taxi missions, Roman will text Niko and say that the other drivers were getting jealous of Niko hogging all the fares and tells him that he should "Use his fists" for money instead. After the mission Roman's Sorrow, the missions will no longer be available to Niko for the rest of the game as Roman's cab business was burned down. Luckily, Roman's Taxi missions are not required for 100% Completion.

Rewards
Grand Theft Auto III
 * The Borgnine cab spawns at the Borgnine Taxis company in Harwood. (100 fares)

Grand Theft Auto: Vice City
 * All taxis gain hydraulic jump capability. (100 fares)

Grand Theft Auto Advance
 * The Borgnine cab spawns at the Portland Hideout. (50 fares)

Grand Theft Auto: San Andreas
 * All taxis gain unlimited nitrous and jump capability. (50 fares)

Grand Theft Auto: Liberty City Stories
 * The Bickle '76 taxi spawns at the Mean Street Taxis company. (100 fares)

Grand Theft Auto: Vice City Stories
 * All taxis gain hydraulic jump capability. (50 fares or $5000 cash made)

Grand Theft Auto: Chinatown Wars
 * All taxis are bulletproof. (15 fares in a row)

Completion of the taxi mission also counts towards 100% completion of the game

Note

 * In Grand Theft Auto Advance the player gets the reward after 50 fares, however it needs to do 100 fares to count the mission completed.
 * In Grand Theft Auto IV doing taxi missions isn't required for 100% completion of the game nor does it bring any achievement or bonus apart of a small amount of money, usually no more than $20-30. It was likely implemented for the sake of realism, and to go along with the plot early on in the game, as well as an excuse to help the player familiarize himself with the road layout while gaining some cash. Unlike the other taxi missions, no time limit is imposed on the fares. Some fares will net the player considerably less cash if they require crossing one or more of the toll bridges.

Trivia

 * In Grand Theft Auto 2, if the player drives a taxi nearby pedestrians, one of them will sometimes get in, but no destination nor mission/time limit is given. As long as player is driving his taxi with a passenger inside, he'll get $1×multiplier every 1 second. The passenger will simply exit the vehicle randomly when the car is stopped or if the player crashes too much.
 * In GTA III, if Claude is pulled out of a Taxi by a pedestrian at the same time that a fare gets into a taxi, the fare ped will stay seated in the backseat. The screen will say "Taxi Mission Ended" after a few seconds, even if Claude immediately gets back into the car. The ped, however, will never move from his seat unless the player activates another Taxi Mission, where the new fare will pull the ped out of the backseat and get in.
 * Due to a glitch in GTA III, the player can transport people around in any car besides the standard Taxi, or Cabbie. To do this, the player must enter a Taxi cab and hold the sub-mission button. Keep holding the button and exit the cab. Then enter the car to whichever one the player desires. Once in the new car release the button and the mission will start.
 * In GTA III, pedestrians as well as gang members can act as fares. Even after passing all the story missions where all the gangs hate you (Mafia, Yardies etc.), they sometimes will get in your car as a fare and act like normal peds and won't even try to kill you.
 * On the PC and Xbox version of Grand Theft Auto: San Andreas, a glitch occurs which prevents any fares to be available, making the mission impossible to complete. It happens if the player has crossed the maps boundary (e.g. flying too far away from San Andreas). It is therefore advised to do this mission very early to avoid this glitch.
 * In Liberty City Stories fares may occasionally spawn in impossible-to-reach locations, such as the pedestrian mall in Chinatown. If this happens, simply leave the vicinity of the fare and another will spawn.
 * In Liberty City Stories and Vice City Stories, if the taxi becomes too damaged while carrying a passenger, the passenger will leave the vehicle but the mission will not end in failure. Instead, the game will add some time to the clock which will, presumably, be enough to get to a Pay 'n' Spray, after which the mission resumes. Using the Pay 'n' Spray during the Taxi Driver mission costs $100 per use, as usual, which differs from GTA San Andreas in which the service is free of charge during the mission.
 * The Taxi Driver mission in Vice City Stories is considerably more difficult than other GTA III-era permutations. In VCS, aside from the usual pick-up and drop-off missions, occasionally Victor will be required to take fares to more than one destination. On other occasions he will be required to discreetly follow another vehicle (during which the countdown clock is deactivated). In yet other missions, he will be required to ferry a criminal between robbery jobs, resulting in a wanted level.
 * In GTA IV after ten fares you will get a text from Roman saying you were hogging all the fares; after that you can no longer do taxi missions.
 * The Guiness Book of Video Game Records ranks taxi missions as the most lucrative legal job.

Vehicles

 * Taxi
 * Cabbie
 * Borgnine
 * Kaufman Cab
 * Zebra Cab
 * Bickle '76
 * Cabby
 * Roman's Taxi