It wasn’t too long ago that car industry experts were predicting a world in which we were all streaming videos or taking a nap while our cars were tooling us safely down the highway. Self driving cars were destined for the short-term future. So what happened? Why are self driving cars still just a fantasy?

The world is certainly closer to self driving cars compared to where we were five years ago. But not by much. We made great strides in the first few years of development, thanks primarily to equally speedy developments in big data, artificial intelligence, and deep learning. But progress has stalled. So much so that the New York Times declared last summer that self driving cars are still “way in the future.”

Follow the Money

Self driving cars are certainly a goal worth pursuing. But car companies got way ahead of themselves. It could be that they put too much faith in technology. It could be that they don’t fully understand how the human brain works. But the biggest impediment is money.

It’s not that car companies aren’t willing to put money into research and development. They are. But they don’t have enough money to overcome the fundamental problem with self driving cars. That problem is human beings.

If a manufacturer is ever to build a viable self driving car suitable for the world’s current road infrastructure, that car is going to have to be able to anticipate human actions. For instance, it’s going to have to anticipate pedestrians darting into the street. Not only that, it’s going to have to figure out how to avoid the pedestrian without hitting other cars.

Machines Making Moral Judgments

Such a scenario creates a very sticky situation. Given the choice to hit a pedestrian or collide with another car, the computer that runs the self driving car is faced with a moral decision it can’t possibly make. Machines don’t think, let alone consider moral decisions. They only respond to data.

The problem doesn’t end there. Self driving cars will have to be able to anticipate the actions of human drivers still driving traditional cars. The only way around that problem is to simultaneously ban all traditional cars at once, replacing them with self driving cars. But that presents yet another money issue. No car company or government would be able to produce enough money to do that.

Rebuilding the Infrastructure

The only way around the inherent limitations of self driving cars is to completely rebuild our infrastructure. Consider the self driving vehicles that dominate so many international airports. Those vehicles work just fine because they operate on a closed system. We can control vehicles on closed systems; we can’t control them on open systems.

There isn’t enough technology or money in the world to develop self driving cars that can work flawlessly on open roads. There are just too many variables. Imagine the wireless network that will be required to facilitate millions of cars all simultaneously communicating with a driverless car network.

If governments were willing to build an entirely new infrastructure, self driving cars would be more realistic. But of course, they don’t have the money either.

So that’s where we stand. Self driving cars are likely coming in the future. But don’t expect to see them on the roads in large numbers within the next 10 to 20 years. It could be 30, 40, or even 50 years from now. We just don’t have the technology to pull off right now. We don’t have the money to create that technology, either.