Step 3 calls for linking vehicles to the infrastructure through sensors in and along the road, along with the traffic signs, traffic signals, and lane markings that augment the driving environment.
Imagine driving your car onto a connected highway. The highway asks you whether you wish to be driven autonomously, and if so, you provide information for your trip. The highway then takes over. Once the trip is complete, the highway tells you it's ready to return control of the car to you. If you're ready, fine. If you're not ready (if you're asleep, for instance), the highway parks your car nearby in a safe space, where it will wait until you've finished your nap and you're ready to resume traveling.
That dream — infrastructure-enabled autonomy — is within reach. But realizing it won't be easy, and it won't be cheap. The job of developing transportation infrastructure has historically rested with government agencies. Can cash-strapped governments handle the additional cost of sensor installation on top of routine road maintenance burdens? Or will this step require a new model of collaboration between governments, automakers, and other players?