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The last step entails the work plan and providing the necessary feedback process, that is, comparing the pavement and treatment performance with that predicted by the PMS, is crucial for improving the system’s reliability.

Figure 1 PMS Structure
4. GIS Technology and Benefits
A GIS is a computerized data base management system for accumulating, storage, retrieval, analysis and display of spatial (i.e. locationally defined) data. A GIS contains two broad classifications of information, geocoded spatial data and attribute data. Geocoded spatial data define objects that have an orientation and relationship in two or three-dimensional space. Attributes associated with a street segment might include its width, number of lanes, construction history, and pavement condition and traffic volumes. An accident record could contain fields for vehicle type, weather conditions, contributing circumstances and injuries. This attribute data is associated with a topologic object (point, line or polygon) that has a position somewhere on the surface of the earth. A well-designed GIS permits the integration of these data. The sophisticated database in a GIS has the ability to associate and manipulate diverse sets of spatially referenced data that have been geocoded to a common referencing system. The software can transform state plane coordinates and milepoint data to latitude-longitude data and vice versa.

A GIS can expand the decision making on repair strategies and project scheduling by incorporating such diverse data as accident histories, economic needs hazardous materials shipment and vehicle volumes. A GIS can perform geographic queries in a straightforward, intuitive fashion rather than being limited to textual queries, A GIS/PMS can be used to build projects through spatial selection, can compute traffic impacts of various PMS plans and can incorporate the results of life cycle forecasts into measurements of future mobility.

4.1 Data Collection
In pavement management process first step is to collect and record the condition of the roadway segments. A series of computer displays showing the segments color-coded by the various attributes would greatly facilitate the process of data entry and editing. Omissions in the data collection effort would be immediately apparent from segments in the roadway showing no data. Errors in measurement or coding would also be readily apparent.

In electronic data collection, equipment makes it feasible to scan a roadway from a moving vehicle and automatically record pavement distresses on a microcomputer. If the data were to be entered directly into a GIS database, this procedure could produce an instant map display of the road condition.

4.2 Preliminary Analysis and Interpretation
In the traditional PMS, the highway engineer transfers some of this tabular information to a base map by hand as a step in understanding the data. For example, he might construct a map showing the severity of rutting or block cracking or create a map indicating the overall performance index. A GIS that integrates the database attributes describing the pavement condition with a cartographic display of the road network can be used to create any number of illustrative visual displays of the status of the road system.