• The routing (static) behavior of the network
هذه المحاكاه تتطلب شروط وخطوات وهي كالاتي
By collecting and analyzing urban freeway traffic data from multiple sources, specific Iowa-based calibration factors for use in VISSIM were developed. In particular, a repeatable methodology for collecting standstill distance and headway/time gap data on urban freeways
was applied to locations throughout the state of Iowa. This collection process relies on
the manual processing of video for standstill distances and individual vehicle data from radar detectors to measure the headways/time gaps. By comparing the data collected from different locations, it was found that standstill distances vary by location and lead-follow vehicle types.
Headways and time gaps were found to be consistent within the same driver population and across different driver populations when the conditions were similar. Both standstill distance and headway/time gap were found to follow fairly dispersed and skewed distributions. Therefore, it is recommended that microsimulation models be modified to include the option for standstill
distance and headway/time gap to follow distributions as well as be set separately for different vehicle classes.
There were two main data collection efforts in this research. The first data collection effort was collecting individual headway/time gap data. In order to collect individual headway data, a number of options were investigated, including manual collection, loop detectors, laser-based collection, video/image processing, and radar-based collection. These options were evaluated with a number of goals in mind for the data collection, including the desire to have timestamped individual vehicle data, especially speed, vehicle class,and lane assignments.
Manual collection was deemed too resource intensive, loop detectors could not be moved to different locations, and no laser-based or video processing options were found to meet the goals of the data collection as well as the selected option.
In the end, it was determined that Wavetronix’s SmartSensor HD side-fired radar detectors best accomplished all of these goals.
By watching a playback of the videos, a counting procedure is done using software that registers each input and the time on the video that it occurred.