If the Terminator had the ability to just turn himself into a cruise missile and wipe out Sarah Connor's city, there'd be no movie. In other words, to make sci-fi stories work, the writers often have to add completely arbitrary and pointless limitations to whatever futuristic technology turns up.
But in the name of plot and drama, they sometimes wind up giving the people of the distant future gear that doesn't even work as well as ours does now, in the boring old present. For instance ...
6Every Post-Apocalyptic Film -- Bicycles (Seriously)
We've seen it in The Road, Terminator Salvation, Dawn of the Dead, Book of Eli, The Walking Dead, Mad Max, Falling Skies and many, many others. One of the main problems of living in a post-apocalyptic wasteland is that the survivors have to be constantly on the move, because otherwise it would just be two hours of watching people slowly die.
Which, to be fair, is pretty much The Road's plot synopsis.
Whether they're trying to reach some sort of fabled vestige of civilization, looking for resources or simply trying not to be eaten by zombies, the survivors are always moving from point A to point B, and that means either walking over insane stretches of possibly radioactive desolation or fighting other people for gas. That's just the way it is, though, because if the whole world has gone to shit, how else are you gonna get around?
So What's Missing?
How about grabbing a bike? In most of these films, there always seems to be a gap between having a vehicle and gas and being shit out of luck, as if no other possibility existed.
"If only there were some sort of middle ground between cars and easily spooked animals!"
Why don't they ride bikes? Did all the zombies eat them? Did the nukes somehow specifically target bicycles but miss all the cars? Bikes are cheap, fast and easy to maintain, plus they require no fuel and they're freaking everywhere -- literally the only reason we can think of for why they are never used in these films is that they would look kinda ridiculous.
Bikes: Worse than being eaten by a zombie.
In The Road and Book of Eli, the protagonists spend pretty much the whole movie walking across hostile territory and never so much as consider looking for some bikes. It's like they never even existed. And before you tell us that Eli wouldn't be able to ride a bike due to his condition -- if you can aim a bow and arrow and win a machete fight, you can ride a damn bike.
There's blind and then there's Daredevil blind.
Not only are bikes considerably faster than walking -- the average human walking speed is roughly 3 mph, and the same effort applied on a bike is 15 mph -- but they are also much more discreet than cars. In Terminator Salvation, the characters can rarely get into vehicles without attracting giant murder robots, which you'd think would at least make them consider building some bicycles out of Terminator scrap parts.
In The Walking Dead, the Dawn of the Dead remake and pretty much every zombie film ever, the protagonists use motorized vehicles to get around, and they inevitably break down, leaving the characters to run. Again, there is no situation in which traveling by bike or at least keeping one strapped to the roof of the car wouldn't be beneficial.
"Yes. This is absolutely the best plan for this situation."
How It Would Have Changed Things:
In Dawn of the Dead, they actually show a character riding a bike inside the mall, but as soon as the characters are forced to leave the place, they completely forget such a thing exists. Given the traveling speeds we showed you before, using bikes instead of running away by foot would have made them exactly five times less likely to be torn to shreds.
In Terminator Salvation, guess what the young Kyle Reese was doing when he was captured by the robots: arguing over gas. Had Marcus, Kyle and the other kid traveled on bikes (or possibly one of those three-seat tandem deals) there would be no need to stop for gas and it would have been a completely different movie from then on.
"Maybe putting up with those terrible shorts would have been worth it."
The biggest difference would have been made in films like Book of Eli and The Road: Had people thought to utilize bikes, every grueling journey would have been much faster and therefore much easier, and in the case of The Road, much less likely to make the audience want to die.
"All of this is happening because you asked Santa for a PlayStation, son. Remember that."