Several corporations recently received California’s first autonomous car driving permits:

On Tuesday, Audi became the first car manufacturer to receive a California autonomous car driving permit (as of this writing, Mercedes-Benz and Google have also filed for and received permits). The permit was presented to Audi by Sen. Alex Padilla, who signed the state’s new autonomous vehicle laws that went into effect Tuesday; the law will allow for the legal testing of autonomous vehicles on public roads…

One is the specific mention of a visual indicator that clearly signals to the driver when autonomous mode is engaged. Making sure the driver is completely familiar with the technology and understands when the car is under machine control versus human control is something carmakers must get absolutely right. Consider what GM is doing with its Super Cruise technology, which allows the car to take over steering and pedal operations in certain highway conditions. Earlier this month GM announced that Super Cruise will be available in select 2017 model year cars. Those cars will likely have the same indicator that we experienced when testing Super Cruise—a large light bar on the top of the steering wheel that indicates when the car is in control (green), when the driver needs to take over (red), and when the driver has control (blue). Hard to miss that. Oh, and it issues an audible alert as well.

Something else to consider: According to the permit, should the driver be unable to take control of the vehicle during an emergency or system failure while autonomous mode is engaged, “the autonomous vehicle shall be capable of coming to a complete stop.” Pretty important! But also a little scary when you think about a car just stopping on the highway. After all, the permit doesn’t say the car must be able to safely pull off the road and come to a complete stop. And in reality, that’s probably asking a lot for now. It’s a reminder that if we want to test autonomous vehicles in the public domain seriously, we have to understand there will be risks…

Lastly, it’s worth noting that the permit calls for an extra device—separate from the data recorders already required in cars—to specifically monitor and record the autonomous systems and their sensors. On top of that, the information must remain accessible for three years. As optimistic as lawmakers and auto manufacturers are about the potential for autonomous vehicles, they also know that one bad accident could stymie progress and reaffirm the public’s worst fears. In case an accident does happen—and eventually, it will—at least they’ll know exactly what went wrong.

Some interesting extra pieces to these permits. All of this suggests that there are still some important things to sort out before driverless cars hit the roads in large numbers.

A few other possible additions that came to mind:

1. An indicator on top of the car or with the front and back lights that shows other drivers that the car is in autonomous mode. We haven’t heard much how such vehicles would change their behavior based on the drivers around them. Say someone doesn’t like their speed and so they tailgate the car, an action that sometimes leads to the front driver speeding up. What would an autonomous car do?

2. A running set of easy-to-understand output from the autonomous car to the driver. It is one thing to provide an indicator that the car is running itself but another to give feedback to the potential driver. Granted, these vehicles are likely making a ridiculous number of calculations per second but I’m guessing some users would like to know what the car is “thinking” as it acts.