Jan de Bont, director of both Speed and Speed 2, says that Speed 3 might happen depending on the story, as well as the original cast's availability.
Speed's director says a third film may still happen. Speed premiered in 1994. The film not only became a critical and commercial success, but picked up two Academy Awards as well. Speed 2: Cruise Control was released in 1997. Unlike its predecessor, though, Speed 2 was almost universally panned by critics, who lambasted the questionable acting and spotty storyline.
Speed stars Keanu Reeves as Jack Traven, an intrepid LAPD officer. Jack learns that a bus has been rigged with a bomb, which will explode if the vehicle slows below fifty miles per hour. As a result, Jack races against the clock to save everyone on board, while sparks fly between him and Annie Porter (Sandra Bullock), one of the bus passengers. In contrast, Speed 2 is set on the high seas; Bullock returns as Annie while Jason Patric portrays protagonist Alex Shaw. The two are on vacation aboard a cruise ship when it's hijacked by John Geiger (Willem Dafoe), the film's antagonist.
Jan de Bont, who directed both Speed and Speed 2, states in an interview with Collider that Speed 3 might still be a possibility. De Bont emphasizes that it all depends on the story, although he adds that he isn't usually a fan of making sequels. De Bont also says that he would want the original cast of Speed to return as well. You can check out de Bont's full quote about the future of Speed below:
"It depends on how the story is, I think. Generally, I’m not a huge fan for sequels. I had in my contract that I would do a sequel. If you have to, you have to have the cast to want to come back too because, otherwise, you have to tell a whole new movie. Because some of the first one was so much centered around him and about him, the awkwardness a little bit in him being a hero. And that awkwardness of being in a position to be a hero is … That worked really well for him but it doesn’t work well for other actors. And it’s really hard to find that same kind of feeling back."
Reeves was initially supposed to reprise his role in Speed 2, but ended up backing out. Although Patric replaced Reeves, it was instantly clear that the dynamic between him and Bullock wasn't the same. As such, de Bont is absolutely right that both Reeves and Bullock should return if Speed 3 is to be a success. However, the two actors are now incredibly busy. Reeves is hard at work on The Matrix 4, while Bullock is one of the most prolific stars in Hollywood. Even if Speed 3 did get off the ground, it's hard to see when Reeves and Bullock's schedules would clear up to shoot together.
There's a lot of fan speculation on where Speed 3 could take place. Speed centered around a moving bus and Speed 2 occurred on a cruise ship. To that end, there are countless possibilities for Speed 3's setting, including an airplane or a train. If Speed 3 really does happen, though, fans hope that it will recapture the magic of the first Speed, instead of falling flat like its successor.