Survey Information
Background
Aerial Surveys
In the fall of 1998, Skycomp conducted a series of aerial photo-surveys of highway traffic quality in the metropolitan Atlanta planning region. The purpose was to obtain traffic quality information to support regional planning activities. Using the mobility and vantage point of fixed-wing aircraft, a photographic inventory and quantitative measurement of traffic quality was made on the backbone of the transportation system. Approximately 500 miles of highways were selected for the survey, and included all of the freeways approaching downtown Atlanta, plus several major signalized highways (the survey area map is available here. These selected highways were photographed during morning and evening peak periods of commuter travel (a detailed description of the survey methodology is on the Methodology page). The result was a set of photos and data representing average traffic conditions of the surveyed highways as of autumn 1998. This data formed a base line for future comparisons so that the effects of changes on the system could be monitored.
In the fall of 2001, the survey was repeated on the same set of highways, using the same methodology. Again, the result was a set of photos and data representing average traffic conditions on the surveyed highways. Also, with a second set of data points, it was now possible to make comparisons related to the 1998 baseline survey.
As the value of this monitoring program became clear, a decision was made to extend the primary network of highways out to the boundaries of the larger (21-county) Atlanta planning region. Extending the boundaries of the survey region involved approximately 250 miles of freeways that had not yet been surveyed. In the spring of 2002, these extended segments were photographed, utilizing the same methodology of the previous surveys.
In the spring of 2004, the scope of coverage was extended further to include an additional 1,500 miles of high-volume signalized arterial highways from throughout the 21-county planning area. This regional arterial network, together with the extended primary network, forms the backbone of the region's state highway transportation system.
Most recently, in the fall of 2005, the extended highway segments from 2002 were added to the original segments from 1998 and 2001, and the combined network (approximately 750 miles) was surveyed once again
Survey Data and Deliverables
The three primary products of the aerial traffic surveys are:
- Quantitative Survey Data: The raw and processed data - vehicle counts, segment densities and levels of service derived from the survey photos and calculated in the database (more information on data reduction is available on the (more information on data reduction is available on the Methodology page).
- Qualitative Analysis: Graphical maps and written observations provide context for the data. Comments often document the extent and duration of congestion at a specific location, while graphical maps provide a quick qualitative overview of the data.
- Interactive web-based slide shows: Selected photos from the survey flights and special maps and graphics provide a visual representation of the data and the analysis. All of the survey data and deliverables described above are available in various formats through the GDOT web site.