Due in class Tuesday, May 4, 1999

Instructions

Your mockups and scenarios should consider the factors from the Cognitive Walkthrough discussion, namely issues of users' tasks and experience and how that compares with actions in the interface. However, your mockups and scenarios may be more narrative (story-like) than the formal Walkthrough procedure. You should have about 8 to 12 interface (screen) mockups with a paragraph explaining each as part of a scenario using your proposed interface. You should write a one to two page introduction to summarize your understanding of the Traffic Signal System. You may not be able to describe every function or requirement you would like in your scenarios. Explain such extensions in a one page summary at the end.Turn in completed assignments in class on May 4, 1999. Late assignments lose 10% (of the 10%).

Remember that text should be typed or formatted while graphics may be drawn by hand neatly. Also, include your name, student number, and the tittle of the Assignment, "Assignment 2: Mockup."

Client's Revised Problem Description --Requirements I

1. City Plan. The system should be general purpose and reusable but an example city plan is given below.
2. Traffic Signal Devices. Assume that the traffic signal devices are equipped with cellular communication devices that create a network for communicating messages about state and commands for changes. UTA personnel might send commands to halt traffic or alter time duration of signals. The traffic signals are also equipped with digital cameras. These might be used by software to detect unusually heavy traffic. Using the cellular network, the signals may automatically coordinate the flow of traffic to reduce congestion. Of course, signals are also equipped with buttons for pedestrians to request walk signals. During most of the day, the signals run themselves either by timing or by the cameras monnitoring flow. At night, the flow of traffic is determined by the cameras.
3. UTA Private Interface. There will be two user interfaces to the system. The UTA Private Interface (UTA-PI) will enable authorized UTA personnel to log in, monitor signals and traffic flow, and make alterations. The primary alterations are to the timing of the signals or to stop traffic altogether. UTA personnel may allow automation to make most decisions for them but need to approve unusual situations such as unusually heavy traffic or intervention during accidents.
4. UTA Public Interface. The second user interface is a Web page that the public can access to monitor traffic or even get live "CAM" views of their favorite intersections. This interface is called the UTA Public Interface (UTA-PA).
5. Synchrony. At any given time, several different entities might be attempting to alter the state of the traffic signals. The signals may be making automated adjustments based on their camera data about the density of traffic. Also, several authorized UTA officials may be logged in and sending conflicting commands. You can hypothesize different ways of handling these conflicts but the conflict policy must be clear and visible in the interface.
6. Security. Only authorized UTA personnel should be able to log in to the UTA-PI.
7. Usability. The system needs to be easy to learn and safe to operate in case of emergencies! Some of the users will have no familiarity with computer interfaces.
8. Reliability and Robustness. The system is not expected to crash. However, if it does, the safety of the public is the primary consideration.
9. Platform. The choice of platform is not of interest to UTA but they think PC's will be cheap and perhaps useful for other applications. However, you get to decide.