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 access into Alderney via car; it connects northern Westminster in Algonquin to southern Alderney City in Alderney. While the tunnel is a four-lane, two direction connection, the tunnel's road bottlenecks to 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. The prominent mission it was used in was the Tunnel of Death.
The tunnel is guarded by the LCPD officers with police-booths at both ends, which may occasionally depict a police officer inspecting the trunk of a parked car; the tunnel also comes equipped with LED signage that inform 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; the latter is a popular spot for multiplayer, especially for Free Mode. 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 Abraham Lincoln, which the Lincoln Tunnel is turn named after.
- If you stand 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. However, in GTA III, the movie was filmed in Porter Tunnel. This shows some relationships of places (except Portland Island) in GTA III and GTA IV: Porter Tunnel connecting Staunton Island and Shoreside Vale, and Booth Tunnel connecting Algonquin and Alderney.
- An interesting sight can be witnessed over the Algonquin access road to the Booth Tunnel: due to the topography of the land (the further inland you go, 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.
- If you enter the Booth Tunnel on the Alderney side it looks white inside on the ground but no matter how fast you go towards it, it would go to the greyish color.
- Right before the second curve in the tunnel, there is a painting depicting a blue, red and orange line dividing Alderney and Algonquin, implied to be the state line. Strangely, if you look at the Radar, or pause and look at the large map, when you're right in front of the painting, your location marker will place you right on the coast of Algonquin, not even in the West River.