The relative accuracy of linear and aerial measurements may vary from one place to another but on the other hand, accuracy requirements become less stringent as we move up to smaller scales. Therefore, maintaining a comprehensive metadata on the various data sources with their accuracy levels is very crucial. Also, when linear features such as roads and highways are compiled at a relatively large scale, it is recommended that a generalized version of those features be derived when they are displayed at smaller scale in order to reduce GIS application performance degradation. However, when facility data has been compiled as point features at a given scale, they can be re-projected at the smaller scale “on-the-fly” by the application software without excessive performance degradation.