The movie opens with a madman holding a group of hostages in an elevator. The cable has been blown in half and the elevator is suspended perilously by its emergency brakes. These too have been wired with charges which will be blown if the madman's demands for cash go unmet.

A daring L.A. cop (Keanu Reeves) and his sidekick (Jeff Daniels) descend the shaft and connect a cable to the top of the elevator. Their clear thinking saves the day, at least after a series of close calls. Thwarted in his evil efforts, the madman expresses his disdain by setting up yet another bombing attempt.

He rigs a bomb underneath a city bus and configures it so that it can be blown three different ways. There's the usual timer, a remote radio-activated detonator, and a speed-activated switch. Once the bus exceeds 50 mph (81 kph) it can never go below 50 mph again without being blown up. Of course, the bus driver doesn't listen to Reeves' impassioned exhortations to keep it below 50, and so the stage is set for a really wild ride.

After some more hair-raising events Reeves finally ends up in charge of the bus with Annie (Sandra Bullock) driving. The bus runs into the traditional L.A. traffic jam on the freeway and has to depart for city streets, leading to all sorts of entertaining mayhem as the bus mows down street signs and sideswipes everything in sight.

When the bus sideswipes a car parked behind a tow truck the car goes up the truck's tilt ramp and flies forward through the air for some distance. Although the camera gives us few details of the actual collision, it's ridiculous to think a sideswipe could ever impart the momentum to a stationary car required for it to zoom up a ramp and go airborne.

The police finally direct the bus to an unused section of highway, but alas it requires a hard left turn. Again, the camera fails to provide the needed information for analysis. The passengers also collect on the right side to counterbalance the bus's tendency to roll and the bus does go up on two wheels. We can't say for sure that it couldn't be done, but it does appear unlikely.

The highlight of the whole movie occurs on the empty freeway. No one realizes that it's missing a fifty-foot section of an overpass bridge until it's too late. Since they can't turn around, Reeves decides to speed up and jump the gap. "Oh boy," we thought, "projectile motion." We excitedly took out our calculators and prepared to pause the VCR so we could measure the take-off angle. The bus appeared to be going up an incline and we ran the VCR in slow motion so we could pause it at exactly the right spot. Much to our surprise the take off angle was zero! The top of the bridge had a rather lengthy flat spot. In other words we were being asked to believe that a bus could fly straight across a fifty-foot gap.

When we watched the supposed jump in slow motion we compared the position of the bus to objects in its background. It appeared as though the back of the bus actually dipped significantly below the level of the take-off point as it traveled partway across the gap. This would have put it below the landing point at the other end of the gap and the bus's undercarriage would have collided with the end of the unfinished bridge.

The bus's front end rose because it either drove up a short ramp, giving it an upward impulse, or it was lifted by cables. Background for the scene was most likely inserted using movie magic. Evidently, the moviemakers thought viewers would accept the jump if the actors seemed sincerely terrified and the scene was edited using lots of quickly changing camera angles and dramatic music. We have yet to talk to anyone who was fooled by the camera work and thought the bus jump possible. It obviously wasn't.

After another series of improbable escapes and near misses glossed over by rapidly changing camera angles and dramatic acting, we end up at the grand finale. It starts with the usual back-off-or-I'll-blow-up-your-girlfriend stuff and progresses to a typical fight scene on top of a moving subway car. Although it was off camera, both our hero and the bomber evidently scrambled up the special ladder labeled "this way to the top of the subway, visitors welcome". The bad guy did fail to take note of the sign which said "watch your head", but then he was, after all, a maniac.

Back inside the car, the hero finds that the brakes are shot, or at least the controls for them. Since the train is racing toward the end of the line he pushes the speed control to maximum, after deciding it's better to speed it up and jump the track rather than pile into a barrier at the end. As usual we're not given enough details to judge his decision, but we are left wondering. If the speed control works in the upward direction then wouldn't it work in the downward direction? Wouldn't a low-speed collision into what just might be a properly-designed barrier be better than a high-speed track-jumping venture into heaven knows what?

Certainly Speed had a unique premise and succeeded as entertainment. However, it will definitely be remembered for its fake bus jump even by those who don't know the difference between a vector and a scalar and don't even care.

Addendum (01/02/06):

The above review was written before details of the bus jump special effect were released in the special edition DVD. We thought about modifying the above review to reflect the new information but decided not to. Only two things have changed: 1) We now know that the upward rotation of the bus's front was done by a kicker plate—a small ramp similar to the one described above—not a cable. 2) Also we have now recieved e-mails from people who believe the jump was actually made as depicted. At the time the above was written, most people intuitively considered the bus too massive for jumping.

As mentioned above, the jump couldn't have been done as depicted in the movie but not because of the buss's mass—projectile motion equations show that only ramp angle and speed, not mass count—it's because of the flatness of the bridge at the point where the jump supposedly took place.

To create the special effect a modified bus was driven at high speed off the end of an elevated ramp and then allowed to smash into the ground leaving the bus undrivable. Was this a bus jump? Perhaps, but it was not the bus jump. Nevertheless, it was enough of a jump to create confusion.

We have made both paper and pencil calculations as well as computer simulations of the jump and concluded that a bus probably could jump a 50 ft gap and remain drivable. It only needs take-off and landing ramps elevated at angles of around 11° with a take-off speed of around 60 mph (97 kph). There are, however, two problems: 1) the conditions have to be nearly perfect or the bus gets wrecked and the passengers injured or worst case: killed, 2) cars could go airborne driving over a completed highway bridge built to these specifications and so it's not likely to ever find such a bridge.

Our conclusion: if you find yourself atop an unfinished highway bridge approaching a 50 ft gap, in a bus wired with a bomb, which will explode at low speed, don't get your hopes up. As for the movie, extreme improbability is better than impossibility, and besides, who can't help liking Sandra Bullock?