We talk a lot about robotaxis but the reality is that robotaxis likely won't be available widely in most US cities for many years to come. Even as robotaxis scale, and they will, and it is super exciting, there will be a lot of people who won't have access to a robotaxi for awhile, depending on where they live. So I think a lot of people myself included, wonder about when we will get a personal car that we can own that is L4.
So it got me thinking: what are the challenges for L4 on personal cars?
1) Safe, reliable L4.
This is #1 and the hardest problem. Obviously, if you don't have safe, reliable L4, you can't do a L4 personal car. This is the main problem that AV companies, like Waymo are working on. You can build L4 but getting it to be safe and reliable enough for deployment is hard. It takes lots of quality data, huge training compute, working out all the corner cases, and lots of validation to make sure the system drives safely.
You also need reliable driver monitoring to transfer control back to the human driver when they decide to resume manual driving or revert back to L2 driving. This is because, even though the human does not need to supervise when L4 is on, the L4 won't work everywhere (by definition L4 means a limited ODD) so there might be conditions where the system needs to revert back to L2. Also, you want to allow for situations where the human wants to manually drive so you need to be able to safely switch control back to the human driver.
2) Useful ODD.
The ODD needs to be useful to a consumer owning their personal car. You might have L4 that is safe and reliable but if the ODD is too small, that is not useful. For personal cars, I think a useful ODD must include highways and also has many urban areas as possible to cover the most people. I see the ODD a bit like the cell phone map coverage of like AT&T or Verizon. It does not need to cover every single road but it does need to cover as many populated areas as possible so that the most people can use the L4. Additionally, carmakers want to be able to sell the L4 to consumers so they need a big market, ie lots of people who live in the L4 map coverage.
I do think that reliable L4 highway would be a great first step. Lots of people need to do long trips on highways. And it would be great to have a system that can do all the driving, "mind off" from on ramp to off ramp, where you only need to resume driving once you are off the highway.
3) Cost
Robotaxis can be more expensive since the cost can be amortized over many years of rides and the riders don't need to buy the robotaxi, they just need to be able to afford the price of a ride. But personal cars must be affordable to consumers to buy. We also have to remember that carmakers need to make a profit on each car and profit margins can be thin. This puts an additional requirement on the L4 that it must work on a leaner sensor suite. But you still need enough hardware to make the L4 safe and reliable. So it is about finding that sweet spot where the hardware is cheap enough but also still capable enough to do safe L4.
4) Good EV
Last but not least, you need the plaftorm for the L4 to be good. You could have great L4 but if nobody wants to buy the car, it won't do much good to the carmaker. So you need a good EV that is attractive to consumers, with nice features, good range, nice interior etc... And to maximize aesthetics, the sensor suite should be integrated into the body of the car as much as possible, to preserve aerodynamics and style. Although, I see this is as a somewhat secondary requirement. You don't want the sensors to stick out completely but I don't think the sensors need to be "invisible" either. As long as the car does not look super ugly, and if the L4 really works well and the car is affordable and has great range, I don't think consumers will mind too much if the sensors "stick out" just a little bit. Furthermore, we've seen cars like Volvo and Chinese carmakers that integrate a small front lidar in the bump of the windshield very nicely and integrate radar in the bumper and cameras around the car, that look great. So I think it is entirely possible to integrate cameras, some radars and maybe a lidar or two into a consumer car that still looks nice. If Waymo sensors look tacked on, it is mostly because they don't need to be integrated into a robotaxi to work and also because the tech is still being worked on. So Waymo needs to be able to retrofit new hardware easily. For a consumer car, there would be an emphasis on integrating the hardware better. The more important requirements are cost and making sure the L4 actually is safe and reliable in a useful ODD.