Networking key for self-drive cars
Sharing information can cut congestion and save travel time
Sspecifies standardised vehicle-tovehicle communication messages for all cars.
This type of communication builds on the popular IEEE 802.11 Wi-Fi standard, creating a potential “internet of vehicles”.
In the near future, cars will not only be 4G-connected but also linked by peer-to-peer networks once within range using the Dedicated Short Range Communications (DSRC) standard.
From as far as several hundred metres away, vehicles could exchange messages with one another or receive information from roadside units about nearby incidents or hazardous road conditions.
A high level of AI seems required for such vehicles, not only to selfdrive from A to B, but also to react intelligently to messages received. Vehicles will need to plan, reason, strategise and adapt in the light of information received in real time and to carry out co-operative behaviours.
For example, a group of autonomous vehicles might avoid a route together due to computed risks, or a vehicle could decide to drop someone off earlier due to messages received, anticipating congestion ahead.
When vehicles communicate, they need to co-operate
Further applications of vehicle-tovehicle communication are still being researched, including how to implement co-operative behaviour.
Our study shows how vehicles near each other at junctions could share route information and cooperate on their travel routes to reduce congestion.
For example, vehicles approaching a fork in the road could calculate, based on estimated road conditions, that instead of all taking a right turn into the same road segment while leaving the other road empty, it would be faster for all if half the vehicles took a right turn and the others took a left.
This means that instead of a large number of vehicles jamming a route along the path of shortest distance, some vehicles could also take advantage of longer but lighter traffic paths. Vehicles may travel a longer distance but get to their destinations earlier.
MIT studies have also suggested that vehicles co-ordinating routes could lead to an overall reduction in congestion.
Vehicles could also co-operate to resolve parking garage bottlenecks and exchange information to help other cars find parking spaces. Our study shows this can reduce time-topark for vehicles.
A question of trust
There are challenges relating to vehicles being able to trust messages from other vehicles. Also needed are co-operation mechanisms that discourage non-co-operative behaviours and ensure vehicles do not co-operate maliciously.
While seemingly far-fetched, it is not inconceivable that autonomous vehicles might form coalitions to deceive other vehicles.
For example, a coalition of cars could spread false messages about a certain area of a large carpark to con other vehicles into avoiding that area, leaving parking spaces for coalition cars. Two autonomous vehicles could take turns to park at a particular spot and making it hard for any other vehicle ever to park there.
Autonomous vehicles that can ethically co-operate with each other and with humans remain an exciting yet challenging prospect.