Former Rockstar Employee Explains Strange Car Behavior in GTA IV

Cars in the game often swerve to the side on the bridge.

A fan of social networks asked former Rockstar Games technical director Obbe Vermeil about the strange behavior of cars on the Algonquin Bridge. The developer explained that initially a train was supposed to pass on the lower tier, and cars were supposed to dodge the moving rolling stock. Due to a coding error, the train and cars are supposedly moving on the same lane, and cars are forced to swerve.