Rewards¶
The reward of a human agent is the negative of its travel time. The reward of an autonomous vehicle (AV) varies with its configured behavior.
Defining Automated Vehicles Behavior Through Reward Formulations¶
As described in the paper, the reward function enforces a selected behavior on the agent. For an agent k with behavioral parameters φₖ ∈ ℝ⁴, the reward is defined as:
where Tₖ is a vector of travel time statistics provided to agent k, containing:
Own Travel Time (\(T_{\text{own}, k}\)): The amount of time the agent has spent in traffic.
Group Travel Time (\(T_{\text{group}, k}\)): The average travel time of agents in the same group (e.g., AVs for an AV agent).
Other Group Travel Time (\(T_{\text{other}, k}\)): The average travel time of agents in other groups (e.g., humans for an AV agent).
System-wide Travel Time (\(T_{\text{all}, k}\)): The average travel time of all agents in the traffic network.
Behavioral Strategies & Objective Weightings¶
Behavior |
φ₁ |
φ₂ |
φ₃ |
φ₄ |
Interpretation |
|---|---|---|---|---|---|
Altruistic |
0 |
0 |
0 |
-1 |
Minimize delay for everyone |
Collaborative |
-0.5 |
-0.5 |
0 |
0 |
Minimize delay for oneself and one’s own group |
Collectivist |
-0.1 |
-0.9 |
0 |
0 |
Primarily minimize delay for one’s own group |
Competitive |
-2 |
0 |
1 |
0 |
Minimize self-delay and maximize delay for others |
Cooperative |
0 |
-1 |
0 |
0 |
Minimize delay for one’s own group |
Malicious |
0 |
0 |
1 |
0 |
Maximize delay for the other group |
Militant |
0 |
-2 |
1 |
0 |
Minimize group delay and maximize delay for others |
Selfish |
-1 |
0 |
0 |
0 |
Minimize delay for oneself |
Social |
-0.5 |
0 |
0 |
-0.5 |
Minimize delay for oneself and everyone |