Remember in the early 2010s, when automakers like Tesla were promising that their fully autonomous vehicles would be for sale in just a few years? It’s 2020, and so far, those promises have not come true.

In a way, this is a good thing. Manufacturers have yet to perfect the technology necessary to make self-driving cars safe and reliable. Even Tesla, which recently announced its Full Self-Driving system is in beta testing, warns users that “[the system] may do the wrong thing at the worst time.” Testers are required to keep their hands on the wheel and pay close attention. That does not sound like a system passengers can count on to replace a human driver.

The computers are not ready yet

One issue is the time and effort necessary to teach computers to drive safely and avoid car accidents. According to one estimate, to prove that a self-driving vehicle system 10-20 percent safer than human drivers, the system would have to log billions of failure-free miles. That would take decades. One company has logged just 20 million miles on its autonomous vehicles since 2009.

Waiting for the infrastructure

Once one or more companies have a proven self-driving vehicle, the roads in Seattle and around the country will need to catch up. Technology to help autonomous vehicles communicate with each other and learn about potential hazards ahead will have to be added to city streets, county highways, interstates and wherever else people travel. Otherwise, the vehicles’ ability to avoid serious wrecks will be limited.

That work has yet to begin. In fact, nobody is sure who will pay for these infrastructure upgrades.

Human negligence is still a problem

It looks like self-driving vehicles are still years away. For now, we will have to rely on human driving skills — ours, and those of the other drivers on the road. Unfortunately, this means that drunk driving, distracted driving, road rage and reckless driving will continue to injure people in the Seattle area for a long while.