In the last few years, there has been a consistent buzz surrounding self-driving vehicles, including headlines from Tesla and Uber. However, recent speculation contradicts the rumors and dates a future full of autonomous driving further into the future.

According to a recent Vox article, several hurdles stop self-driving vehicles from hitting highways sooner. First, it’s the technology.

Why discuss the possibility if the technology isn’t up to date?

When it comes to the programming required for vehicles to operate on the roads, engineers have successfully created programs that allow cars to seamlessly navigate the road without a driver watching for road hazards and other cars. However, there are limitations to these programs. For example, sensors may be impeded by specific weather conditions or visibility in certain environments – similar to most human drivers.

There is also the problem surrounding a time estimate. Many companies assumed they would have the technology perfected and tested by the early 2020s. As scientists continue to work on autonomous vehicles, they are finding the timelines are constricting and not accurate to the actual amount of time it takes to redesign and modify the current self-driving programs.

Second, there’s a general stigma surrounding self-driving cars.

Even if the technology is perfected, many experts worry about the general perception surrounding self-driving vehicles. Many drivers express negative criticisms and emotions that could degrade the success of autonomous cars.

You have to be able to prove and change the general reception to these vehicles before they become mainstream on the roadways. Tesla has seen moderate success with introducing self-driving elements while still allowing drivers to recalibrate and transition to a new way to drive.

There are even statistics that suggest more self-driving cars on the roads may reduce accidents as you take away the possibility for human error. But that won’t be for another few years as reputation and technology catch up to specific companies’ expectations. For now, Pennsylvanian drivers will need to rely on themselves and other drivers to ensure safety on the streets.