Highway Variable Speed Limits Using CAV Moving Bottlenecks

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Solution Overview

Problem

Traditional VSL control methods rely on fixed detectors and historical data, failing to account for real-time traffic dynamics and driver variability, leading to suboptimal traffic management.

Innovation Solution

A method and system for active control of VSL on highways that constructs a mixed traffic flow scenario considering driver individuality, using connected and autonomous vehicles (CAVs) to form moving bottlenecks, employing multi-agent reinforcement learning to optimize speed limits dynamically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional fixed detectors and historical data analysis are used for VSL control, then the system is simple to implement, but it fails to reflect real-time traffic dynamics and driver variability

Engineering Contradiction:
Improveaccuracy of traffic condition reflectionVSAvoidcomplexity of control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent transitions from static fixed detectors to dynamic multi-agent reinforcement learning that adapts to real-time traffic conditions and driver behaviors. The system continuously learns and adjusts speed limit controls based on changing traffic dynamics, making the control strategy dynamic rather than fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces an intermediate layer of intelligent agents that process information between detectors and control systems. These agents use reinforcement learning to interpret traffic data and generate optimal control decisions, serving as a mediator that bridges raw data and actionable control strategies.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If traditional VSL control methods are used, then the control strategy is easy to implement, but it cannot account for driver individual characteristics and reactions

Engineering Contradiction:
Improveability to account for driver individualityVSAvoidcomplexity of control model
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by having different agent models for different driver types (aggressive, conservative, normal drivers). Each agent is specialized to handle specific driver characteristics, allowing the system to adapt control strategies to local driver behaviors rather than using a uniform approach.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes parameters by adjusting speed limit controls based on detected driver types and behaviors. The reinforcement learning agents modify control parameters dynamically according to observed driver individual characteristics, enabling adaptive response to varying driver reactions.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If real-time multi-agent reinforcement learning is used for VSL control, then traffic safety and efficiency are improved, but the computational complexity and training requirements increase

Engineering Contradiction:
Improvetraffic throughputVSAvoidtraining time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent performs preliminary action by pre-training the reinforcement learning agents offline before deployment. The agents are trained extensively in simulation environments beforehand, so that when deployed in real-time, they can make rapid control decisions without requiring continuous online training, thus reducing real-time computational burden.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses copying by creating multiple agent instances that replicate the learned policies. Instead of running complex real-time optimization for each control decision, the system copies the pre-trained agent models and applies their learned strategies directly to real-time control, reducing computational complexity while maintaining performance.

Inventive Principle:
Principle #26Copying

4Reliability

If diverse training scenarios are generated by Poisson distribution, then the model generalization ability is improved, but the training data requirements and computational load increase

Engineering Contradiction:
Improvemodel generalization abilityVSAvoidtraining data volume
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent uses dynamic scenario generation where training scenarios are created on-the-fly using Poisson distribution rather than requiring large static datasets. This dynamic approach generates diverse traffic conditions programmatically during training, reducing the need for extensive pre-collected data while improving generalization.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS20260070551A1Method and system for active control of variable speed limits on highways
Publication Date: 2026.03.12 CHANGAN UNIV
  • US20260070551A1 patent drawing
  • US20260070551A1 patent drawing
  • US20260070551A1 patent drawing

AI summary

A method for active control of variable speed limits on highways includes: (a) a mixed traffic flow scenario considering driver individuality is constructed, and scenario parameters are set; (b) traffic state data for a merging road scenario is acquired; (c) an agent is trained using the traffic state data as state variables to obtain a speed limit control optimization model; diverse training scenarios are generated by Poisson distribution during training, an optimal speed limit value and an appropriate speed control location are selected within each control cycle T, and a moving bottleneck is generated using a moving bottleneck variable speed limit constructed based on connected and autonomous vehicles. A system for active control of variable speed limits on highways is further provided.