Satellite Imagery Based Mapping of Road Network, Traffic Volume Demand, and Traffic Related GHG Emission Inventory:
Graduate research by Katherine Osborne (B.S. 2008, M.S. 2009) and Jessica Headrick (B.S. 2008, M.S. 2010), The University of Mississippi
The research work described in this post was conducted at the Center for Advanced Infrastructure Technology (CAIT) – University of Mississippi as a part of the National Academy of Sciences (NAS)/ United States Agency for International Development (USAID) project “Development of an Intelligent Transportation System (ITS)‐based traffic management model for metropolitan areas of Pakistan with Karachi as a pilot study.”
This was a joint research project of the University of Mississippi (UM), USA under the ‘US‐Pakistan Science and Technology Cooperative Program’ and NED University of Engineering & Technology (NED) which was funded by the Pakistan Higher Education Commission (HEC), Pakistan, 2007-2010. Dr. Waheed Uddin was the US-side project director. Both CAIT researchers, Katherine Osborne and Jessica Headrick, used spreadsheet data files and GeoMedia Pro geospatial software to produce several spatial maps including geographical information system (GIS) maps of landuse and traffic volume demand.
Katherine Osborne is currently a Water Resources Specialist and EIT at AMEC Environment & Infrastructure, Nashville, TN. She trained most of the CAIT staff on using geospatial software for landuse mapping and satellite imagery for traffic volume estimating. She created a scientific sampling design and collected 2007 traffic count and volume data from 40 road sections using 1-m satellite imageries considering road class and location within the city (outskirts and inner city).
Jessica Headrick is an EIT in the Planning Division at the Mississippi Department of Transportation in Jackson, MS. She further analyzed the sample traffic volume data using an analysis of variance procedure and found significant effects of the road class and location of road with respect to outskirt and inner city areas. She finally mapped these results in the entire city, created a detailed 2007 traffic daily volume map, and calculated greenhouse gas (GHG) emissions from road traffic. The 2007 daily road traffic volume was estimated to be 9.3 million vehicles (71% in inner city and 29% in outskirts) which was calculated to produce GHG emissions of 5.5 million tons carbon dioxide in Karachi in 2007.
Benefits of extracting road data from satellite imagery include: creating an available inventory database for asset management, providing an accurate source for maintenance and emergency management, easy data access, improved readability depending upon imagery resolution, and a more up-to date source of information. The benefits of imagery based traffic count and volume data are that it can be used: in remote areas where traffic count devices are not accessible, for filling missing data for traffic volume demand studies, and to reduce labor, time, and cost. The volume demand maps can be used for other traffic planning and evaluation studies: congestion zones, bottlenecks, addition of lanes, capacity and level of service (LOS) analysis, vehicle emission impacts, warrant for traffic signals etc.
Dr. Uddin’s note: The Pak‐USAID Karachi Metropolitan ITS Project implemented geospatial technologies and collaborated with City’s ITS video surveillance network system for traffic management to improve urban traffic flow, reduce vehicle emissions and air pollution, and decrease road crashes and public health costs in Karachi. An international transportation conference and regional workshops were also held to disseminate the methodologies and key results to other major Pakistani cities and universities. The project trained 1,566 Pakistanis (13% women) in Karachi, Lahore, Islamabad, Risalpur, Sukkur, and Khairpur, as well as 44 Americans (57% women). More info on the project achievements are available at the National Academies web site.