Goofs

When the jewelry thieves' Cadillac races through the tunnel, the car's grille goes from being in perfect shape to completely ripped out and back repeatedly.

When Kit and Madelyne come out of the water after the explosion, the sky is cloudy. When they are saved a few minutes later, the sky is clear with bright sunshine.

When the explosion reaches the mouth of the tunnel, the cars entering stop in straight lines. After Kit and his passengers get out of their car, completely different vehicles are scattered everywhere, and some have overturned.

After George meets the first survivors, he hands them his flashlight and heads off to look for more people. In the next shot, he is holding the flashlight.

When the fireball reaches Madelyne's car in the tunnel, a four-door Oldsmobile is next to it. When she gets out later, the Oldsmobile is now a two-door Lincoln Continental.

When the fans are shut down so Kit can get into the vent system, he gets past the first fan, and it kicks on. The other fans aren't moving that fast. Once the first fan kicked on, the other fans should be spinning much faster due to fluidic coupling, similar to a torque converter in a car.

When the fleeing car starts crashing into the sides of the tunnel and other cars Officer Tyrell yells "Breaker breaker" into his police radio. That's CB lingo and not a proper police call to dispatch.

With all the abandoned vehicles, oil would be washed from the engines and fuel systems, yet no oil floats on the water.

At the beginning of the movie, two lanes of traffic go into the tunnel, with a solid, double yellow line between them. This road marking doesn't necessarily mean two lanes of traffic traveling in opposite directions, but that passing or changing lanes is severely restricted. Signs at the mouth of the tunnel say "Stay in Lane" and "Lane Crossers Will be Summonsed".

The water, entering the tunnel from the river above, should be brown and dirty from the mud and sand above the tunnel ceiling.

The cars in front are clearly empty when the tunnel entrance collapses on top of them.

The survivors climb the stairs in the sandhog bunker to a small room below a maintenance parking lot. Since there were 8 steps to the hatch under the booth, then 20 steps to the parking lot, the lot was about 30 feet above the tunnel. The lowest point of the Hudson River is 93 feet deep, plus 10 feet of bedrock on top of the tunnel, so the lot would be under 60 feet of water.

When the jeweler is getting into his car, the jewelry sign behind him is misspelled 'jewlery'.

When George falls into the hole, it should've instantly filled with water. The water in the rest of the tunnel was almost waist deep.

When the character Ashley is asked by Roy to video him just before he tries to find a way out the cameras battery symbol is clearly flashing empty yet she is still using it a few scenes later.

Grace (Vanessa Bell Calloway) and Norman (Barry Newman) were leaving for the night thinking everyone has died, before they find the survivors in the carpark. So how are they at the pier when Kit (Stallone), and Madelyne (Amy Brenneman) are rescued from the water. Everyone thought they had died. Did the rescue boat phone Grace and Norman to come and see Kit and Madelyne be saved.

Kit finds some 80-year-old fuses underwater, but they work. Fuses were not waterproof in the 1920s.

When Kit tells the chief about the simulation that was done in 1994, both actors said "1993", when the scene was filmed, but "1994" was dubbed in later. In a later scene, when Kit refers to the simulation again, she says "1994".

When Madelyne is leaving New York early on on the movie, singing along (and modifying the lyrics) to "New York, New York," the first shot of her in the car clearly shows that her mouth is not moving.

When Eleanor is holding the pipe in George's mouth after he has been pinned under the truck, the sleeve of a bright pink wetsuit is visible under her shirt sleeve.

When George tells Ray Nord the tunnel is blocked off, Roy leaves to check out the damage for himself. His shadow is cast on the wall behind him as he walks down the tunnel toward the wall of fire. Another shadow of somebody running appears in front of Roy's shadow for a few seconds, then disappears.

The tunnel goes between New York and New Jersey. There is no reason for New York State Prisoners (the bus shows a New York Department of Corrections logo) to be going between those states.

After blowing the manhole, there is now a direct entry to the ventilation system. Once the tunnel started filling with water, it would've leaked into the ventilation duct, cutting off the path for the the fresh air and suffocating any survivors.

The fireball turns almost every car in the tunnel to a burnt-out shell, breaking windows and body work and killing everyone. The flames are strong enough to flip cars, but do not penetrate the prison bus, even as windows smash as it rolls through the tunnel. Madelyne also survives, even though her windows are open. When she climbs out later, all of the pillars and window frames are badly burnt.

Whilst the fire ball rips through the tunnel, all the survivors are in the cars expect for George who was standing in his booth. If the fire is strong enough to turn cars over and melt them how did George survive.