Due to the increased level of detail, nearly all streets in Grand Theft Auto IV have names, which are are supposedly useful for locating landmarks and completing vehicle-theft missions, however names are not labeled on the in-game map so players need to use the printed, unindexed street map that comes with the game to locate a specific street. There are no street signs visible, either. Many streets and roads in Grand Theft Auto V are also named, but only major highways have signage. GTA V also introduces numbered state and federal highways; however, in-game, they are referred to by their local road name instead of their number, with Route 68 as the only exception. If the player zooms in close enough on the in-game map, street and road names are highlighted beside the neighbourhood name.
In Grand Theft Auto IV, some street names in Liberty City have certain themes associated to them. In Algonquin, the east-west streets are named after minerals, gems, and metals; north-south streets named after American cities, usually capital cities. In Broker, the east-west streets are named after famous cowboys; north-south streets are named after American Indian tribes. In Dukes, the east-west streets are named after leaders in the American Revolution; north-south streets are named after Revolutionary War battles. In Bohan, east-west streets are named after break dance moves; north-south streets are named after prisons. In Alderney, north of the Hickey Bridge, streets are named after mountains; between the Booth Tunnel and Hickey Bridge, streets are named after cult leaders; between the industrial district and Booth Tunnel, streets are named after famous inventors and some tools.[2]