Road hotspot warning system based cooperative concept

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!

[email protected]