NPC

Other race vehicles in single player and In-Game Traffic are spawned and computer-generated to suit the preference of the game. They count as an NPC (Non-Player Character) as they are controlled by an Artificial Intelligence (AI). Other NPCs include pedestrians, cops, and opponents. Airplanes and ships may count as an NPC.

Opponents
Opponents in Single Player races are computer-generated. They can find their own quick route in order to achieve checkpoints. They can maneuver through traffic, jump over bridges, and reverse when they crash. They will not use their horn, they will not use stunt ramps, use hidden passageways in buildings, and very rarely, cut through grass. They will always travel on roads when racing. They can take shortcuts through alleyways, the Chicago Mall, or tunnels. Some opponents have their own means of finding the quickest possible route, while others may take the typical route to win a race. Opponents can repair themselves when they are in damage penalty during Circuit Races but not in Checkpoint Races. They will not turn themselves upright when they roll over, and may not break down barriers to continue Circuit Races.

Traffic, Pedestrians, Cops, and others
Traffic and Pedestrians are meant to blend in with the city's background. They will follow traffic regulations and flow with other traffic. Traffic can use turn signals, emergency flashers, and stop when they are crashed by another object, or vehicle. They may honk, panic, or scream various quotes in game. In-game Pedestrians walk along sidewalks and will duck, mode aside or jump in panic when another vehicle crashes in their direction. The Airplane will travel through the sky and pass overhead on Meigs Field (Airport) but not touch the ground for landing on the runway.

Cops will not appear on the map if they are stationary (on patrol). They will appear as red and blue when they come after the player's vehicle (with the exception of Ford Mustang Crusier) with sirens. Cops will try to overtake the car in order to stop or distract it. They may stop after a while. In Cruise, they are spawned randomly on the map but they will always be pinpointed in specific locations in races.