Picture this: It's your dream vacation. You're in a car with a driver who's taking you safely from one end of Delhi to the other, your friends are chatting in the backseat ― and you feel like throwing up. Not metaphorically. You're actually nagging the driver to find a way out of rush-hour traffic to pull over, and while nothing ... comes out, the feeling is still miserable.

Well, I felt miserable, anyway.

It was probably the stop-and-go traffic that made me feel so sick. My friends in the backseat were totally fine. And I followed all the rules, too: Sit up front in the passenger seat, eyes on the horizon and not stuck in a book.

Read more: BMW, Daimler team up to develop self-driving cars

So I wonder why I got motion sick… again.

In fact, why do loads of unlucky folk get motion sick more frequently and more easily than others? And where does the dreaded nausea come from?

First, I'm told, calling it motion sickness is wrong.

"It's not a sickness in the sense that there's a bodily malfunction somewhere," Dr. Uwe Schönfeld, an electrical engineer and medical physicist, told DW.

One of Schönfeld's areas of expertise is the nausea some of us experience when we travel. In June, he starts a new research project at Berlin's renowned Charité university clinic. But more on that later. Back to motion sic―  uh, kinetosis, to use the correct medical term.

"The symptoms come from an overload of our balance system," Schönfeld explained.

"This system was developed, through thousands of years of evolution, for normal human movements and postural control. When we use today's motorized vehicles to get from A to B, we are exposed to more intense movements than those that are part of our normal human repertoire of movements. And that can overwhelm our movement sensors," he says.   

Certain behaviors can make the stress on our balance system even worse.

When you're reading in the back of a car, your eyes transmit a message to your brain that the world around you is still. But the motion sensors in your inner ear pick up the movement of the car. These two competing pieces of information are referred to as a "sensory conflict." And that's what pushes your balance system over the line and makes you feel nauseous.

Motion-sick across the world

I don't read in cars. And yet: The experience in India was just the most recent entry in a long line of unpleasant travel memories. There's hardly a country I've visited where I haven't felt the bile rise in my throat.

In Delhi it was rush-hour traffic.

On a Germany vacation, it was Bavaria's winding mountain roads that made me nauseous ― and I was driving the car myself. You might have thought that wasn't possible, like my travel companions who made me the designated switchback driver for that very reason. But they, and it would seem you too, were wrong.

In Egypt, I baffled a guide by being the first person he had ever taken on a Red Sea snorkeling tour who got motion sick during the actual snorkeling. I don't even need a boat to get seasick!

 

Those who get it most

"It's like with sunburn," Schönfeld explains. "Some people are extremely sensitive to it, others not at all. Most people who have it are born with it."

Some estimates suggest that around 30 percent of the world's population experiences symptoms of kinetosis at least once in their lives. For reasons still unknown to scientists, people of an Asian background are thought to get travel sick more often than others.

Hormonal changes play a role, too, which is why kinetosis is particularly likely to hit youth going through puberty and women who are pregnant, or menstruating.

Helpful pills with side-effects

I have learned my lesson, of course. I now take travel medication whenever my itinerary includes potentially risky trips by airplane, ship or in automobiles ― trains are actually fine for me.

But there's a downside with these anti-motion-sickness pills: They make you drowsy.

Some more, some less, but you're never 100 percent there. That's less of a problem during a long-haul flight, but inconvenient if you plan on sight-seeing after a half-hour car ride.

"Those meds are antihistamines, which suppress a certain trigger mechanism in our brain," says Schönfeld.

That trigger mechanism is the one that makes you throw up when things get shaky.

Good thing that gets suppressed!

Unfortunately, though, antihistamines are known for making you tired. You might have experienced that with anti-allergy medication. 

Magic glasses?

That's one of the reasons why people have been looking for new, creative ideas to avoid the drowsiness of the pills, while not throwing up at the same time.

Among those ideas: "Boarding Glasses" developed by French start-up Boarding Ring, which partnered with car-maker Citroen.

The glasses have a thick frame and four rings instead of two. In addition to the ones you look through, there are two on the side of your face as well.

And inside the frame there's a blue liquid.

"The liquid moves around the eyes in the frontal direction (right-left) and in the sagittal direction (front-back)," according to the company's website.

This, it's said, creates an artificial horizon in the peripheral field of view — the sides of your vision — without disturbing the central vision (what you see straight ahead).

And as if by magic, "the sensorial conflict instantly disappears and motion sickness fades in a few minutes."

There haven't been large-scale studies to scientifically test the "Boarding Glasses," but anecdotal evidence from users suggest they work.

How not to get sick in a self-driving car

Fighting motion sickness is going to become even more important with the introduction of autonomous vehicles. A major selling point is that you can message friends or watch movies on a tablet while the car drives for you.

But that is also precisely what causes kinetosis in many people.

Here's where Schönfeld's new study comes in.

This summer will see the start of a new research project on motion sickness and autonomous cars at the Charité hospital in Berlin. Schönfeld and his team will collaborate with automotive engineering experts from the Technical University Berlin to figure out how autonomous cars could be constructed to not make people sick, which situations are particularly problematic, and what the driving style should be.

It's going to be important work. After all, even the nicest self-driving car won't be any good if it has to constantly pull over for you to lose your lunch.