摘要: |
The methodology used in the production of a geographic information system for the management of 20,000 km (14,247 mi) of highways in Spain is explained. Pavement evaluation systems provide an exhaustive amount of information about highways. A multifunction device provides information about international roughness index, rutting, megatexture, macrotexture, microtexture, cracking, curve radius, longitudinal, and cross slope. Some of these parameters break down into data such as those relative to both wheel tracks or into different intermediate levels. Additionally, all of these data can be taken at a very high sampling rate, a rate as high as one every 10 cm (4 in.). All of this information, which is useful for having detailed knowledge of the highway's condition, can be useless (because of unmanageability) if the right tools that permit highway administrators to perform a quick overall analysis of the highway network are not applied. These tools should be capable of grouping data of different types, depending on the study to be performed, and should also be able to represent the data in graphical form. These groups should be significant for each type of data, average value, variance, maximum value, minimum value, and so forth. Maps and graphics have been demonstrated to be good analytical tools that allow a quick and easy overall view of the whole network, making it easier to locate questionable or bad areas and their extent. Once these areas are found, a more detailed analysis on a smaller scale can be made by reanalyzing the data. At the same time the system is capable of integrating various types of information (traffic, deflections, etc.). To do this, the reference system is flexible, permitting its use with different types of data and different scales. The reference system used is the arch/node system. Accordingly, the highway network is divided into sections. The end of a section, which will be the beginning of the following section or an intersection where different sections converge, is designated a node. This system allows data on a specific point (accidents, signals, etc.) to be perfectly referenced in a section at a distance from the node of origin. It also allows lineal data along a segment to be referenced by situating the node in a section starting at a distance from the origin and with a specific length. This reference system can be very well adapted to the Spanish highway network, which is entirely referenced by means of kilom |