This is the second of four follow-on articles to Do Smart Highways Now—Delay is Not Smart, in which an integrated automated highway system is envisioned. This article will describe how the vehicle flow system and all the cars connected to it communicate with each other.
For the system to guide each car through an efficient and safe path to its specific destination, it needs to process the status and travel data from all of the cars together. Each individual car on the other hand just needs a tiny fraction of the overall information resident in the larger system—it uses only data about its immediate environment (nearby cars and road transitions) and the system data pertaining to its current route.
When you start your car, it immediately checks in with the vehicle flow system in the (computer) cloud. Your car and the system establish together a listening session with each other, in which the system awaits a request from your car to join in an active navigation session. No, it does not spy on you or record your conversations—remember, the software is open source and audited, greatly reducing any chance of such skulduggery. Your car’s transponder reports to the central system your location, direction and speed (for the safety of other drivers and their navigation), but it does nothing to control the drive train until you join it to a control session and activate a route that you have chosen.
Once you’ve decided to engage a route and select (say) “Join,” the transponder tells the system to prepare your car to engage the central navigation system. The system listens for your selection of destination, optimally via voice but it also could be through a touchscreen on the dashboard display. You then confirm the route by selecting (saying) “Go,”—and you’re “off to the races” (figuratively of course!). The dashboard will advise that you can release the controls (steering wheel and pedals), and it’s now the system that has assumed the task of responding to traffic and road conditions.
At this point, the amount of data transferred in both directions increases significantly between your car and the vehicle flow system. Telemetry data transmitted would include a close analog to the Automatic Dependent Surveillance-Broadcast (ADS-B) system used for aircraft. But the car’s transponder reports, along with the location and travel vector data it was already sending, additional data about the car’s steering and drive train. This would also include servo motor status covering the degree of steering wheel turn and its effect on the actual tire position, the amount of brake pressure required to slow the car a specific amount, the response to acceleration commands including the points of transmission downshift for speed increase or hill climbing, and related control data points that a human driver would consider subconsciously as a matter of course.
As the vehicle flow system is controlling objects moving at highway speeds, network timing is critical. Timing of actions must be precisely synchronized between the car’s transponder and the distributed central system as well as adjacent cars. It would be essential to include a capability such as Precision Time Protocol (PTP), an established standard for time synchronization on networks. Augmenting these timing packets with the highly precise timing available from the GPS equipment onboard every vehicle would add further accuracy and reliability to the system.
The car’s controller unit for the drive train is an absolutely critical component in this process. It’s function is analogous to the cerebellum of a biological brain. For example, when the central system sends a command to change to the next lane (such as to be in position for an upcoming exit ramp), the controller unit awaits the few milliseconds necessary for the transponder to confirm an all clear to maneuver. The transponder does this by pinging the adjacent cars’ transponders (it already knows their network IDs and is monitoring their position status), and alerting them that it is about to make the specific maneuver sent from the central system (which the other cars have also received from the central system as relevant telemetry data).
Using the telemetry data from the system, the on-board transponder, and the car’s sensors (including degree of tire traction, which will vary with road conditions), the controller unit executes the commanded maneuver. For a lane change, this includes considering the car’s current speed and its speed relative to the adjacent cars nearby. The controller unit activates the turn signal (as a human driver would do, especially considering any manually controlled cars that might be nearby) and changes lanes, adjusting speed and degree of steering wheel turn to complete the maneuver. Finally, the transponder reports to the system and adjacent cars that it has completed the maneuver, and the event is closed for all nodes involved.
The vehicle flow system really earns its keep when anomalies occur, such as an accident up ahead or a car that has to stop due to a flat tire or other malfunction. (Instances of law enforcement stopping a driver for a moving violation would be practically eliminated, because the vehicle flow system will have prevented these violations from occurring in the first place.) Anomalies occurring in the current infrastructure are circumstances in which traffic jams form almost immediately, and everyone is late to their destination. In these cases, instead of independent drivers reacting in ways unexpected by the other drivers, the vehicle flow system computes multiple re-routes in a matter of seconds—and everyone is back on their way with minimal delay.
The system could manage planned (vs. random) changes even better. A frequent example is construction zones. You’ve likely been in a back up where there’s reversible one way traffic with the help of workers alternately displaying those Stop/Slow signs at each end of the zone. Imagine how much more efficient it would be if those workers had (instead of just their radios) portable control systems that communicated locally with all of the cars’ transponders in the affected zone. Using instantaneous local traffic data from the portable units on site, the system could better reduce the degree of back up at each end. It also would be much safer for the workers!
The vehicle flow system is able to do this from the status and destination data it has for each car in the system, and from the instant data from the point of traffic stoppage or impediment. Often when drivers “bail out” to an alternative route, they are not the only ones with such a good idea. The problem is you can never know for sure how many others are onto your secret workaround until you’re inexorably committed to it. As a critical mass of other cars converge to clog the alternative route, you’re just as stuck or stuck in a worse traffic jam than before. “I should have never made that turn, but nothing to be done now!”
What the vehicle flow system does is something trending toward artificial intelligence, but I think’s it’s a matter of opinion whether to call it AI. And it really doesn’t matter what you call it—what it does is what’s important. The vehicle flow system might be characterized as doing something akin to sorting, except at a very large scale and wholly integrated system wide. The sorting analogy might help in further describing it (acknowledging that the “sorting” being done is multi-layered and complex both vertically and laterally). With usual traffic, the system would be “sorting” the independently travelling cars against the route and status of every other car instant along the route of each separate car. With a traffic anomaly (e.g. an accident or construction), the “sorting” continues except with the added parameters from the anomaly for route computation. This is why it might not be unusual for the system to take you on a different route to work each day of a week—if you’re in a carpool, that could be grist for some entertaining conversation!
As the vehicle flow system updates each car’s route, it also advises every other nearby car of the updated telemetry data. Those updates include when a car has reached its destination and its trip has concluded. At that point on your route, you select (say) “Disconnect,” and the system returns your car to manual control. Park your car (it would take further infrastructure build-out to include parking too), and realize that getting there was not nearly as awful as it used to be.
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