Road Hotspot Warning SystemBased on
Cooperative Concept
Hao YE
Nottingham Geospatial Institute
University of Nottingham
Research Motivation
Every year millions of accidents occurred on the roads, particularly on road hotspots where there are higher accident risk than other sections of road. Existing hotspot notification techniques are often static and predefined, which are relatively unreliable because they cannot consider a range of accident contributory factors together, for example, those factors referred to human, vehicle, road and environment.
Source: Traffic England & Highway Code
This project was to create a cooperative concept based hotspot warning system platform which integrates a range of archived and real-time data sources together in order to support drivers with better advice and reliable warning for potential dangers. The other application of this system is to provide data collection of real-time traffic data stream at road hotspots for transport monitoring and management
Research Approach
Risk Level: highest risk!Time of Period: winter, 7-9 pmPrimary Causation: turn too fastTraffic Condition: congested roadWeather Condition: rainyRecommendation: reduce speed
vRoad Hotspot
Application Server
Internet Databases
Research Objectives
• To provide a comprehensive review of current cooperative concept based systems, including existing applications, techniques and potential challenges;
• To identify system requirements of a cooperative hotspot warning system, and design system architecture to perform the required functions;
• To use GIS-based techniques for analysing historical accident hotspots areas, and integrate analysis results onto road digital hotspot maps;
• To design, develop and establish a system prototype platform based on the designed system architecture;
• To prove the feasibility of system design concept by demonstrating the prototype platform at selected case study areas, and evaluate the performance of the prototype with field experiments under realistic traffic conditions;
System Architecture
Data Exchange LayerData Analysis Layer Physical Devices Layer
On-Board Unit
Group Vehicles
GNSS
Cellular Network
Data Package
Integrated Traffic Database
GIS platform
Information Dissemination
Historical Accidents
Accident Hotspots
Prototype System Design
GNSS
State Estimator
CAN-Bus
Data Manager
Message Encoder
Human Machine Interface
Drivers
Wireless Communication
On-Board UnitIn-vehicle Sensors
Cellular Network Infrastructure
Client Vehicle
Information Display Module
WirelessCommunication
Message Encoder
DataManager
Digital Hotspot Map
Hotspot Algorithm
Application Server
Control PlatformTransport Operator
Other Database
Road Site Hotspot (1~2m)
Lane-Level Hotspot (~3m) Road-Level Hotspot ( > 10 m)
Standard Lane 3.65m
v
Road Boundaryx
y
Precise Positioning Module
• Road-level hotspots: much larger than general road width e.g. school zones, construction zones, intersections, and roundabouts.
• Lane-level hotspots: small hazardous areas close to lane width e.g. emergent curves, high-risk sites on road lane, lane entry points
• Site-based hotspots: microscopic, hazardous or temporary areas on the road, e.g. road work sites, icy sites, potholes, temporary road work sites, etc.
Digital Hotspot Map Module
Drivers
Human-Machine Interface
Map Database
Analyse road hotspots
Extract road hotspots
User-Centric OBU platform
• Digital Hotspot Maps were created by using geospatial techniques to analyse historical accident database in GIS and integrating to system platform
Map Integration
Communication Module
• Communication is based on 3G cellular communication as it can provide long-distance communication range, higher data rate, lower delay and cost.
• This module was built on end-to-end TCP/IP protocol which means each vehicle can connect to the server by a unique IP address, the implementation is based o nTCP sockets for reliability purpose
• The main function is to support real-time hotspot warning, as well as bi-directional data exchanand updating ge, such as hotspot map updating and traffic data collection
Application Server
Program Program Program
Socket Socket Socket
Internet (TCP/IP)
Internet (TCP/IP)
Internet (TCP/IP) Internet Program
Socket
Internet(TCP/IP)
Client Vehicles
Hotspot Warning Algorithm
Message input
Hotspot Proximity
Acquire hotspot attribute
Dangerous time period
Yes
Yes
Yes
Yes
Yes
• Time• Traffic• Weather
Vehicle Status
ExtensiveMonitoring
Yes
Dense traffic flow
Yes
Yes
Bad weather
hotspot warning
• Speed• Acc• Heading
Yes
No
No
No
No
No
No
The algorithm includes a hotspot proximity part and an intelligent warning part. The hotspot proximity part mainly uses GIS method to check entry/exist status of vehicle, while the intelligent warning part adopts a range of simulated real-time data to demonstrate the feasibility of hotspot warning.
Messaging Mechanism
Message ID Message Type Time Stamp Position Velocity Message CheckBSM
Message ID Message Type Time Stamp Position CAN-BUS Velocity Message Check
Brake Turn Light Rain Sensor Light Sensor ∙∙∙∙ Other Sensor
ESM
Message ID Message Type Time Stamp AccType AccNum Advise Message CheckRHM
V
Hotspot Boundary
Basic Safety Message (BSM)
Roadside Hotspot Message (RHM)
Extensive Safety Message (ESM)
Client Vehicle
Prototype Implementation
Client GUI Application Server GUI
• The prototype demonstrators were developed based on Windows platform by programming in C#. The current system platform includes the functions such as GNSS data acquisition, GIS hotspot integration, vehicle tracking, reliable wireless communication, hotspot algorithm decision making and bi-directional data exchanges.
A-Road
Minor Roads
Intersections
Experiment Route
(a) Application Server(d) Video Data Recorder
(c) Client Platform
(b) Testing Van
Experiment Installation
Field Experiment
NGI
Leaving HotspotEntering Hotspot
Hotspot Area
Performance Evaluation
Application ServerClient
Thanks for your attention!
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