Designed as the only road tunnel to link two islands in Liberty City, the Booth Tunnel, along with the Hickey Bridge to the north, are the only points of road access into Alderney. The tunnel connects northern Westminster in Algonquin to southern Alderney City in Alderney. While the tunnel is a four-lane, bi-directional tunnel, the road bottlenecks into two-lane throughfares at both ends of the tunnel, occasionally resulting in the player encountering difficulty exiting one end of the tunnel, especially at the Alderney end, which may not provide sufficient room for the player's car to squeeze though its opening.
Just before the second curve in the tunnel, there is a painting depicting a blue, red and orange line, implied to be the state line, dividing Alderney and Algonquin.
The tunnel is guarded by the LCPD, with manned police booths at both ends. Officers may occasionally be seen inspecting the trunk of a parked car. The tunnel also features LED signage which informs drivers of safety tips and security announcements. Mavericks also spawn on helipads at both ends of the tunnel, one over the Alderney end of the Booth Tunnel and the other in front of the tunnel's ventilation tower on the Algonquin end. In The Ballad of Gay Tony, a Swift initially spawns at the Algonquin end, only to be replaced by a Buzzard upon completion of the game's storyline.
The tunnel is based on the Lincoln Tunnel in New York City, but the tunnel is presumably named after John Wilkes Booth, the assassin responsible for killing President Abraham Lincoln, whom the Lincoln Tunnel is named after.
- If the player stands next to the police officer on the Alderney side of the tunnel for about 5-10 minutes, he will mention about how he was hesitant about taking the job there because he heard that the horror movie, The Tunnel, was filmed there, and he thinks that it may be haunted.
- An interesting sight can be witnessed over the Algonquin access road to the Booth Tunnel. Due to the topography of the land (i.e. the further inland the player travels, the higher the elevation), a short segment of the A/J Algonquin Outer Line, which is in a subway, actually passes over the sloping, surface-level access road.