Site Impact Analysis |
| This page documents the efforts directed towards
developing the site impact analysis capabilities using a GIS database.
The efforts are directed towards using existing traffic engineering
software packages (Trip Generation, Highway Capacity Software)
with a GIS component to manipulate and store relevant data (location,
site characteristics, access points, existing traffic volumes,
forecasted volumes). The goal of the site impact analysis is to supply local jurisdictions knowledge of the process and provide tools that can be used to verify results generated by outside consultants. The site impact analysis demonstrates appropriate datasets useful for the process, show some efforts to manipulate the datasets to make the information displayed and stored in an efficient manor. As stated in the ITE's report on traffic access and impact studies, "study reviews should be conducted or directed by properly trained transportation engineers or transportation planners in agencies that are responsible for development review and approval". It is extremely important to remember that this is only a support tool to guide users in performing site impact analysis. The recommendations in this work are intended to allow the user to verify assumptions and calculation made in site impact analysis performed by outside individuals. The site impact analysis will identify some GIS based datasets that are useful in performing the analysis and selected software packages that are generally used to support site impact analyses. Most site impact analysis are performed to determine the effect of traffic that a new business or development will have after completion. Many individual agencies have there own criteria on when a site impact study need to be performed. Most of these criteria are based on the site generating a specific number of vehicles in the peak hour, or on a daily basis. When a specified number of acres is being developed or when the size of the development exceeds a certain size. When the development occurs in a sensitive area, when financial assessments are required and the extent of the impact must be determined, or when desired by the staff or agency. When the consultant develops a site impact analysis, there are certain items that they should assess before hand and that should be reviewed by the agency. These include traffic counts, the planned roadway improvements, approved background traffic levels, agency policies, existing congested locations, accident data to determine high accident locations, traffic signal system (if appropriate), any neighborhood sensitivities, and any temporary events that would influence the data or outcome of the analysis (from the ITE Manual of Traffic Impacts). The steps to follow when performing a site impact analysis are show in the figure. Select any of the boxes to receive a description of the step. Select any of the options to receive more information or click on the back button to return to the introduction page or the site map button to go to the site map.   |