Statement of the Problem
Vehicle collisions at intersections account for a large percentage of overall traffic accidents. Figure 1 shows three of the most common ways for collisions at intersections.
Figure 1: Common reasons for collisions at intersections
The situations illustrated in Figure 1 account for 65% of injury accidents and 70% of fatal accidents. It is also true that for the past thirty years, the annual fatality rate due to traffic accidents in the United States has been over 40,000.
We can prevent a large number of these accidents from occurring if we could provide drivers with warnings about potential collisions. For example, if a system could warn a car sitting at an intersection that another car is about to run the light, the driver waiting at the intersection would then not immediately start driving the minute the light turns green for him since he would be aware that there could be a potential collision with a car running the light.
Our project concentrates on using technology to provide warnings to drivers about potential accidents and collisions at intersections.
Vehicle Infrastructure Integration
The Accident Warning System we plan on creating falls under a broader system called the Vehicle Infrastructure Integration (VII). This system enables real-time wireless communication between cars and between cars and static intelligent stations or units to help create an efficient and safe transportation system. VII is a massive system whose various applications and technologies are under research and testing in various parts of the world – especially in the United States and Europe. Figure 2 illustrates the many varied applications of VII.
Figure 2: Applications of VII
Dedicated Short Range Communication
Dedicated Short Range Communication (DSRC) is a wireless communication protocol in the 5.9 GHz frequency band with a bandwidth of 75 MHz. It refers to short to medium range wireless communications that offers data transfer in a vehicular ad-hoc network. The IEEE Standard for it is 802.11p. This standard is exclusively for transportation communication systems.
Our project exclusively focuses on the Safety aspect of VII using DSRC. The goal of our project is illustrated by Figure 3.
Figure 3: Accident Warning System at Intersections
From Figure 3, we notice two main components of the accident warning system:
1. Roadside Unit (RSU)
This is a component of the system which acts as the central unit. It is in constant contact with the traffic light in order to determine when the light will turn red. Once it realizes that the light will turn red, it starts treating all messages from the OnBoard Unit as Event Messages. Hence, it uses the speed and location information being transmitted to determine whether the car transmitting the message will run the red light, and if it will, then it needs to warn the other cars of this possibility.
2. OnBoard Unit (OBU)
This is a component of the system located within a car. It constantly calculates the speed and location of the car, and transmits this information to the Roadside Unit. It also receives the warning signal from the Roadside Unit telling it to activate the alarm system in order to warn the driver of whether a car will run the light.
We have further narrowed our goal by placing the following restrictions on our project:
1. Accident Warning System of only whether a car will run the red light
This means that there will be no path and speed suggestion provided to the driver. There will also be no warning for pedestrians crossing the road. The project only deals with warning a driver if another car is about to run the red light.
2. Limitation to only one speeding car
Unlike a real-life scenario, there will only be one car approaching the intersection, and one other car receiving a warning of whether the approaching car will run the red light.
3. Real-Life demonstration
We hope to accomplish a real-life demonstration of the working project.
4. Technical Documentation
A comprehensive documentation will be completed and delivered to the advisors of this project.
This page is maintained by Richa Prasad.
© 2007 University of Massachusetts Amherst • Amherst, MA 01003