The New York Transit Authority for years after the novel and the original film barred its planners from scheduling a train leaving Pelham at 1:23 in the morning or afternoon. Although the policy was rescinded, as a superstition the dispatchers still avoid scheduling a train at that time.
The movie pays homage to Walter Matthau, who played Lieutenant Zachary Garber in the 1974 movie by naming 'Denzel Washington's character Walter Garber. Also, while Lieutenant Zachary Garber wore a plaid shirt and yellow tie, Walter Garber wears a yellow shirt and similar pattern plaid tie.
The title derives from the train's radio call sign. When a New York City subway train leaves to make a run, it's given a call sign based on the time it left and where, in this case Pelham Bay Park Station at 1:23pm.
Ryder says to Garber, "You live, you die, you either go with the current or you fight it, but you all end up in the same place", to which Garber asks, "Where's that, Jersey". Ryder then says, "Yeah, you watch it, I was born there man." John Travolta, who plays Ryder, was born in Englewood, New Jersey.
Garber talks about choosing between purchasing trains from a Japanese company and a Canadian company. Although not mentioned by name, this refers to Kawasaki Heavy Industries and Bombardier Transportation, who have both manufactured subway trains for New York.
The R-142 and R-142A subway cars portrayed in this film are permanently linked into 5-car sets and cannot operate as single units. R-62A 2079, a single car capable of operating alone, was cosmetically modified to resemble a modern car for this film and restored to its original appearance after filming was completed.
James Gandolfini's portrayal of the Mayor is an obvious composite of two real former NYC mayors: his appearance and attitude is clearly based on Giuliani. However, an exchange between him and Ryder, where Ryder teases him about taking an annual salary of only $1, is a clear reference to Bloomberg.
While negotiating with Garber on the phone, Ryder says the hostages aren't getting pizza. In the movie Inside Man, Denzels Washington's character is a hostage negotiator who sends in pizza for the hostages being held in the bank.
The original movie was released in 1974 and the remake in 2009, 35 years later. Robert Shaw starred in the 1974 version and James Gandolfini in the 2009 version. Both men died of heart attacks 35 years apart (Shaw in 1978 and Gandolfini in 2013) both men were aged 51.
In the movie, from the audience's viewpoint, Ryder (John Travolta) is seen wearing an earring on his right ear while Walter Garber (Denzel Washington) has one on his left. Also notice that both of them has only a single earring.
The seemingly bad continuity random shots including rain, over parts of the city, may be actually written off within the story, and reality, as a legitimate weather pattern where rain clouds might just happen to pass over localized areas while raining, leaving the rest of a large area dry. This isn't such an unusual weather event, particularly noticeable in cities.
In the novel, Ryder's mother died of cancer, and his father was bludgeoned by an ashtray. He entered military service, like Vietnam, and perhaps this was the case in the original film, but doubtful in the remake.
In the novel, the Mayor has flu but in the remake he says he always gets flu when visiting schools so wants a flu shot on standby. But the Mayor is ill with something that could be life-threatening. His wife is in the novel but they've separated in the remake because of his infidelity.
In the novel, the ransom demand is one million dollars, and so it was in the original film, but the remake has upgraded it to ten million dollars. Ryder says a million dollar ransom is a corny asking price.
In the novel, the first time we meet the Mayor is at his mansion, having a tryst with a monk, and not on another train like the remake. In the remake, his marriage is in trouble but not for the same reason. The Mayor (Sam in the novel) even considers letting the hijackers keep the train because New York doesn't have a million dollars, which was a lot of money in 1973 when the book was written.
The equivalent of Garber in the novel, is someone named Prescott, and he's not as level-headed as Garber in the remake. He's an operations Lieutenant, and a minor character, and views the escape from the train at transit police headquarters.
At 11 minutes and 26 seconds, a computer falls to the floor with the message "CONNECTION LOST". While Wi-Fi may have been available in underground stations, it is highly unlikely to have existed in the tunnels at the time. While the director's commentary states that this laptop camera represents a 'third eye' on events, it broadcasts nothing further after it fell to the floor.
An officer gives Garber a stainless Walter PPK and puts it in one of the money bags marked with a wire tie on the handles. But later when they get off the train. As one of the bad guys is carrying one of the bags, a gust of wind from a moving train causes a bag to fall on the ground. Garber reaches down and pulls the gun from the bag to put in his pocket. Now the gun is something completely different from the Walther PPK that was originally given to him by the officer .
Fifth and last time John Travolta and James Gandolfini acted together on the same movie before Gandolfini's death in 2013. They had previously worked on Get Shorty (1995), She's So Lovely (1997), A Civil Action (1998) and Lonely Hearts (2006).
The trivia items below may give away important plot points.
The Roosevelt Tunnel built under the Waldorf Astoria to which Ryder uses as part of his escape from the subway is actually based on the secret track 61 which is built under the Waldorf Astoria and was commissioned to help President Franklin Roosevelt keep his use of a wheelchair secret.
The ending in the novel is different to this film and the original; in the original film, the last remaining robber says something incriminating to Walter Matthau, and in the remake, Garber kills Ryder and the cops kill the last two remaining robbers.
In the film, Ryder wants Garber to deliver the money, but in the novel he wants cops to drop it off in ten minutes or he kills a hostage. There is no road accident that makes them miss the deadline or lying to Ryder that they've got the money.
In the novel, the hostages tell Ryder why they need to be released and he says why they can't, but not the remake. An off-duty cop is on the train too but not the remake, where he takes matters into his own hands at the climax. He shoots Ryder in the tunnel, but Ryder dies by electrocution in the original film, but is killed by Garber outside in the remake.