Today’s Wonder of the Day was inspired by Mrs. Clark's Class from River Falls. Mrs. Clark's Class Wonders, “How many cars are on the road at one time?” Thanks for WONDERing with us, Mrs. Clark's Class!

You wake up early. You're a little nervous. You have a huge presentation to give at school today, but you have to iron out a few last-minute details with your fellow students before class starts.

After getting ready, you're out the door and in the car on the way to school. You should have just enough time to meet with your classmates to put the finishing touches on your presentation.

Suddenly, you come to a standstill. What's going on? You glance around and realize you're stuck in traffic. Oh no! Not today of all days…why aren't any of the cars around you moving? You scan the horizon for flashing lights, but all you see are cars in every direction.

Have you ever encountered a traffic jam at the worst possible moment? Whether it's being late for school or missing the first few minutes of a movie, no one likes to get stuck in traffic when you have somewhere to be. While we don't give it a second thought most of the time, we suddenly realize how many cars there are on the road when they've got us surrounded!

If you've ever been stuck in bad traffic, you may have WONDERed exactly how many cars there are on the road at any one time. While that's a great question to WONDER about, it's unfortunately impossible to answer. There are just too many vehicles in the world today!

Way back in the early part of the 20th century, Henry Ford probably never imagined what his assembly line production system would mean for the world. While he hoped to make the automobile affordable for the average American, he likely never dreamed the world would reach the point it has today.

With automobile ownership growing rapidly in countries such as China and India, the worldwide population of automobiles finally eclipsed the one billion mark in recent years. Can you fathom that? There are over one billion automobiles in our world today.

Of course, there's only a certain percentage of those automobiles that are on the road at any given time. The rest of the time, they're tucked away in driveways and parking garages, awaiting the next time they'll get to hit the open road.

When it comes to automobiles, the United States and China lead the way. Today, China has well over 80 million automobiles. That's a lot, but it pales in comparison to the number of automobiles in the United States. Experts estimate the U.S. has over 250 million automobiles!

Some experts believe there could be 2.5 billion automobiles worldwide by 2050. If that happens, traffic jams are likely to be worse than ever! Already, the world has seen some massive traffic jams.

For example, commuters in Beijing, China, were recently trapped for hours on the 50-lane G4 Beijing-Hong Kong-Macau Expressway. Occurring at the end of a busy tourist holiday, the jam was caused by a new checkpoint that required 50 lanes of traffic to merge suddenly down to 20 lanes!

And that's not even the worst traffic jam Beijing has ever seen! In August 2010, large trucks carrying construction supplies on the Beijing-Tibet Expressway snarled traffic into a 62-mile-long jam that lasted 12 days! Can you imagine being stuck in traffic for almost two weeks?

Wonder What's Next?

Tomorrow’s Wonder of the Day features everyone’s favorite uncle!