Volvo has delayed its by four years and will no longer be testing fully-autonomous cars at launch, after initial plans to get the robots rolling by the end of this year. This isn’t very surprising.

The Drive Me program was announced in 2015, and Volvo claimed it would be pushing out 100 new level four autonomous XC90s to families in Sweden to test out its autonomous driving technology by the end of 2017. Similar programs were to be subsequently launched in the U.K. and China.

The Drive Me program has been drastically changed and the new plan is to test limited level two semi-autonomous technologies that require driver attention in a build up to level four testing by 2021.

reported that Volvo ran into problems it couldn’t solve on such a hasty schedule when developing the program:

“On the journey, some of the questions that we thought were really difficult to answer have been answered much faster than we expected. And in some areas, we are finding that there were more issues to dig into and solve than we expected,” Marcus Rothoff, Volvo’s autonomous driving program director, told Automotive News Europe.

One of those issues is the automaker’s reluctance to pick a so-called “sensor set” too early.

“The development in sensor performance and processor capabilities is going so much faster than we expected in 2013,” Rothoff said on Monday. “Because advancements are being made at such a rapid pace, we want to make this decision as late as possible.”

Leave it to Volvo to responsibly admit its technology isn’t ready and appropriately slow down its development, and not just . Instead, the XC90s delivered to Swedish families this month with be optioned similarly to vehicles already available for sale in the U.S., which definitely , and the fancier, hands-off stuff won’t be coming until much later.

Some automakers, like Ford and GM, earmarked public rollout of its technologies around 2020 from the beginning, and it won’t be surprising if other companies end up slowing down their autonomous projects. It’s almost certainly for the better.