References
In addition to the software used on this training website, the following sources were referenced:
Banks, James H. (2002) Introduction to Transportation Engineering, 2nd Ed. McGraw-Hill, San Francisco.
Bullock, Darcy. (2001) Traffic Signal Summer Camp Course Materials. University of Idaho. Moscow, ID.
Kyte, Michael. (1999). Using CORSIM to Model Signalized Intersections - A Short Course. Unpublished.
Roess, Roger P., William R. McShane, and Elena S. Prass. (1998). Traffic Engineering, 2nd Ed. Prentice Hall, Upper Saddle River, New Jersey.
Thau, David. (2000). The Book of JavaScript. No Starch Press, San Francisco.
Project Overview
This section outlines why this project was undertaken.
A synopsis of traditional university education in traffic signal operations:
Traditionally, students are educated in traffic signal operations in the classroom. In this setting, they learn the basic concepts of how traffic operates at signalized intersections and how signals can be timed using some fairly simple equations. From this experience, students typically grasp how to apply the equations to develop signal timing plans, but have difficulty in understanding the cause and effect relationships that are represented by the equations. In addition, it is difficult for students to understand how to implement the signal timing plans in actual traffic controllers.
Importance of traffic signal training:
To maximize student’s effectiveness when they enter the engineering profession it is important that they will be able to visualize how traffic will operate under different signal timing plans. This can only be done by understanding the cause and effect relationships between intersection characteristics, signal timing plans, and the quality of traffic operations.
Goal of the traffic signal training program:
The goal of this program is to provide students with the experience that they need to relate problems to viable solutions and to be able to implement them in actual traffic controllers.
Traffic signal training method:
Students will be trained in an environment where they can interact with a traffic control system called hardware-in-the-loop simulation (HILS). This system is comprised of a traffic controller, a computer running a traffic simulation model, and a controller interface device (CID) that allows the traffic controller and computer to communicate with each other.
Each of the traffic control system components are shown in the figure below, where the traffic controller is the blue box on the left, the computer running the simulation is at the bottom, and the CID is the black box to the right of the traffic controller. The projection of the computer screen represents the animation of the traffic system being simulated, allowing students to see the results of any signal timing plan.
Data is exchanged between the traffic controller and the computer through the cables and the CID. The computer tells the controller when vehicles arrive and the controller tells the computer when the different signals should change to green, yellow, or red.
The advantage of the HILS training environment is that students can learn how to develop signal timing plans through hands-on experience. They develop the signal timing plan using the appropriate equations, translate these plans into something that will work in a traffic controller, implement the plan in the controller, and then see how traffic operates on the computer animation. If the students are curious to see how traffic will operate if a certain parameter is changed, they can change it while the simulation is running and instantly see the effect of that change on traffic operations rather than seeing the change in the output of an equation.