Christos Taxiltaris

Applications of GPS technology in the land transportation system

Abstract The global positioning system (GPS) allows the accurate positioning of an object using satellite signals. There are a lot of applications of this technology in many scientific fields all over the world. In recent years, the rapid increase in the development of the geographic information system technology (GIS) has led to the development of GPS/GIS applications. Therefore, the geometric and geographic information obtained by the use of GPS can be introduced to GIS database and thus thematic maps can be produced. In the framework of this paper, a short overview of applications in the area of transportation in Greece and abroad is presented. Emphasis is placed on an ongoing application in railway mapping, through the presentation of its pilot phase in Greece. The use of modern technologies, the problems identified and the results produced are presented and discussed.

Development of an Integrated Transportation System in Thessaloniki: Current Situation and Future Prospects

The city of Thessaloniki is characterized by severe traffic problems especially in the central area. Two major transportation studies concerning the Thessalonike Metropolitan Area (T.M.A.) have been conducted during the last fifteen years while at the same time there were also a number of short-term traffic management studies in the various Municipalities of T.M.A. The results from the studies show that the use of Public Transport is steadily decreasing while there is a parallel increase in the use of passenger cars. Car ownership will continue to grow during the next ten years, up to the level of many other countries in the EU. In order to have an integrated transportation system, various transport infrastructure scenarios were examined including, among others, the construction of a metro and of a submerged tunnel. Road transport telematics applications were also tested in the city but there is still a lot be done in this sector. Concerning the air pollution due to traffic, CO and Pb concentrations are reduced, NO(2) concentration is stabilizes while O(3) concentration shows an increasing trend at the city boundaries. PM(10) and TSP concentrations seem to be significantly reduced and the same applies to SO(2) concentration.

Analyzing Heavy Goods Vehicle Data Collected on Main Road Network in Greece

The work described concerns the first major study on heavy goods vehicles operating on the trans-European links in Greek territory. The study period coincides with a period in which major development in the national road network took place that required the support by specific studies concerning pavement design, road management, and toll collection. Data were collected at seven specific sites on the main axes of the main national roads. A total of about 3,053,116 records at all sites were collected concerning all vehicle categories. Data were collected using permanent weigh-in-motion (WIM) instrumentation with either rigid or flexible sensors. In addition, comparison measurements were taken from high-speed and low-speed WIM systems to examine the validity of the above systems to be used in law enforcement for overloaded vehicles. Analysis of the data revealed that the initial sets included a series of counts that were not reliable. False data were detected by imposing various physical or technical filters. The consistency of the remaining good-quality data was examined by using simple analysis techniques. In the final stage of the work much emphasis was given in the development of a comprehensive database of WIM measurements. This database is unique for the Greek national road network and is a necessary step in order to provide useful information and support future actions in the area of pavement design and maintenance.