Ramprovisation

Man is only separated from heaven by that which he will not ramp.

—Dr McNinja, The Adventures of Dr. McNinja

A character operating a vehicle is in a tight spot; there's something blocking the path, someplace too high and/or far to reach, etc. What to do? Look for something that would be remotely be used as a ramp, or just build one, to perform a Ramp Jump.

A Sub-Trope of Theme Park Landscape. Not to be confused with Use Your Head, which covers improvised ramming.

Examples of Ramprovisation include:

Anime and Manga

Black Lagoon: Rock uses a derelict ship to ramp the titular boat, then fire a torpedo directly into an attack helicopter.
Happens in Highschool of the Dead.
In Venus Wars, Hiro is being chased by police and surrounded. So he lifts the monobike onto the side of the highway guard rail to make an escape.

Fan Fics

In Kenya Starflight's "Star Wars characters are trapped on Earth" story Eye of the Storm, Darth Vader takes over during a car chase with stormtroopers and uses the Force to pull an under-repair sign across the roadway and use it to ramp over a train, using the Force once more to keep the car stable. It still doesn't handle the landing well, though.

Film

Diamonds Are Forever: while in a chase with police cars in a parking lot, James Bond uses an overturned car as an Improvised Ramp to jump his car to safety. Watch it here, 0:10-0:15.
- The Man with the Golden Gun has a cool broken-bridge improvised ramp that leads to the car making a 360 degree jump.
Speed: a Broken Bridge is used as an improvised ramp (I believe the MythBusters tried it ... turns out the filmmakers cheated and used CGI).
The 2000 remake of Gone in Sixty Seconds used an improvised ramp near the end to bring to a close the big chase scene.
Live Free or Die Hard (aka Die Hard 4.0) has a Ramprovisation so unusual that the hacker lead notes how improbable it is.
At the end of Jackie Chan's First Strike, Jackie uses a conveniently-placed car display ramp to jump a Mitsubishi onto the boat carrying the Damsel in Distress.
In The Lorax, Ted attempts to jump a gorge by making a ramp from a rock and an abandoned board, but the board fails to hold his scooter's weight, sending him hurtling down in to gorge instead.

Literature

Chapter one of Feed ends this way. George uses a hill as an improvised ramp.
Matthew Reilly's books do it every so often. Avoid torpedoes, drive a truck into a fighter plane... He also figured out that the only way to make this trope more awesome is to blow up the improvised ramp behind the vehicle.

Live Action TV

Once an Episode (or more) on The Dukes of Hazzard as they perform their Slo-Mo Big Air.

Video Games

In Midtown Madness 2, you can jump from one embankment of the Thames to the other by use of strategically placed ramps in the Tower of London, and a (convenient) boat in the middle of the river.
Used for many Insane Stunt bonuses in Grand Theft Auto, as far back as GTA 2.
Appears frequently in Total Overdose. Ram's first mission doesn't exactly require one, but strongly encourages it to flee the top of a parking garage.
Just Cause 2: There are absolutely dozens of conveniently placed piles of building materials, collapsed road signs and so on spread around for ramping.

Web Comics

The Adventures of Dr. McNinja has these two examples and gives us the page quote.

Western Animation

Jonny Quest episode "Mystery Of the Lizard Men: while escaping enemy agents in the Sargasso Sea, Race Bannon and his pursuers both use an overturned boat as a ramp to jump their boats high in the air. The 2nd time, Race uses it to turn his hydrofoil into a deadly weapon. Watch it here, at 2:10-2:20 and 4:25-4:30.
Gwen in Ben 10: Ultimate Alien makes her own ramp out of Anodite magic.
Cars: Lightning McQueen uses a wrecked competitor during a race.