The SL-GMS objects were integrated with existing traffic management applications that include windows created with the UIM/X Motif tool, as well as Thomas Brothers maps. The maps were imported into SL-GMS as the base, with the dynamic objects placed on top. The integrated display is seamless to the operator, who can also issue commands through the SL-GMS-created objects.
For example, the operator has the choice of opening several windows on both monitors, each window exhibiting the network’s traffic information in real-time. The operator typically opens at least one window with volume information and another with speed information. Both will display dynamically.
The freeway map displays the traffic data and that information changes in color on the map as the volume changes. When the application software determines that an incident exists, a flashing object will be created at that location on the screen map. The operator clicks on the flashing icon and the ATMS brings up windows to guide him through a dialogue in which he is asked to confirm that the incident exists. As part of one of the confirmation procedures, the system automatically brings up different images from the CCTV. This allows the operator to visually verify the identified incident at the freeway location.
The operator station is integrated with an expert system, initially developed as part of the Testbed program at the University of California in Irvine, which responds to operator input with an action response plan for the operator to perform. The operator may be instructed
to contact the California Highway Patrol and to contact CalTrans Incident Management Response Team or CalTrans maintenance personnel. The ATMS expert system also recommends messages for Changeable Message Signs (CMS) located at critical points along the freeway network. When the messages are displayed on the freeway, the SL-GMS software makes display icons on the operator’s screen which are miniature replicas of the current message on the sign, along with the sign’s map location.
NET is also enhancing the ATMS to provide congestion mitigation through freeway network expert system analysis and ramp metering control. When complete, the enhancement will utilize the SL-GMS software as its interface.
Operators may also use the drag-and-drop capability of SL-GMS objects to manually declare an incident. If the operator believes that congestion warrants the declaration, the appropriate icon is selected and dropped on the map. The expert systems will then begin functioning.
Finally, the TMC personnel can operate the CCTV cameras through the SL-GMS interface. The camera sites are displayed as an icon on the map. The operator clicks on the icon and the system opens a window with the picture from the camera and a graphical camera control panel. The operator clicks on objects on the control panel window to issue camera control commands (pan right, pan left, tilt the camera, etc.) to control the viewing area. All responses and actions occur in real-time.