Traffic Queue Length Estimation Using Density Profiles
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Solution Overview
Problem
Current methods for determining queue lengths at traffic signals face challenges due to the limitations of local data measurement, reliance on manual observation, and the need for extensive detector installation, which are costly and impractical for comprehensive traffic situation detection, especially in urban areas.
Innovation Solution
A method using a data processing device with a traffic model that estimates queue lengths based on density profiles from reporting vehicles' position data, which can be high-precision GPS or mobile phone data, allowing for accurate determination of queue lengths with minimal metrological effort and robustness against faulty data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If loop detectors are installed at relatively close distances to achieve area-wide traffic situation detection, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent introduces a data processing device as an intermediary that receives data from existing loop detectors and uses traffic models to calculate queue lengths. This mediator enables area-wide detection without requiring dense detector installation, as the data processing device synthesizes information from sparse detector locations to infer traffic conditions across the entire network.
Solution Approach 2:
The patent creates a virtual copy of the traffic network through modeling. Instead of physically installing detectors everywhere, the system creates a digital representation of queue lengths and traffic situations based on data from existing detectors, allowing area-wide monitoring through computational models rather than physical sensor duplication.
2Device complexity
If manual traffic counting is used to record traffic situation, then device complexity is reduced, but productivity and data quality deteriorate
Solution Approach 1:
The system enables automatic self-service traffic monitoring by using the data processing device to automatically receive detector data, process it through traffic models, and generate queue length calculations without manual intervention. This automated process maintains simplicity while dramatically improving productivity and real-time coverage compared to manual counting.
3Measurement precision
If video cameras are used for automatic traffic detection, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the data processing device universal by enabling it to work with multiple detector types (loop detectors, video cameras, FCD systems) through a unified interface. This multi-functionality allows the system to achieve automatic detection precision while avoiding the complexity of dedicated video camera systems, as the same processing device can handle various data sources.
4Area of stationary object
If FCD systems are used for comprehensive traffic detection, then area coverage is improved, but measurement precision deteriorates due to thin database
Solution Approach 1:
The patent merges FCD data with loop detector data in the data processing device. By combining these different data sources, the system achieves both comprehensive area coverage from FCD and measurement precision from loop detectors, overcoming the limitations of using either system alone.
Data Source
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AI summary
The method involves positioning a traffic model i.e. Nagel-Schreckenberg-model, for a road segment with a light signal system, where the traffic model provides minimum density profile in a connection of parameter. Position data is detected from a registered vehicle at the road segment. An evaluating process is carried out for determining the density profile that includes a maximum consistency with the determined position data. A tailback length at the light signal system is determined by a traffic model under the provision of parameter of the selected density profile. An independent claim is also included for a device for determining a tailback length at a light signal system, comprising a data processing device.