MySQL-Based Archiving of Traffic and Environmental Data

German motorways are equipped with a vast number of sensor systems. This closely meshed net of sensors is able to collect a wide number of meteorological and traffic parameters including e.g. precipitation intensity, visibility and vehicle data. While different parameters are measured by different systems there is a wide spread of data types and filenames (e.g. separate files for precipitation intensity, visibility and vehicle data). For this reason it may take a long time to provide relevant data quickly and it becomes difficult to analyze and compare parameters. In special cases there is the need for faster availability and it is therefore necessary to develop a system for central storage of this data. The idea to unite all data on an online database server has many advantages. It allows reading and writing additional data independent of time and place. Moreover, a local storage medium such as CD-ROM is replaced by a central and safe system with a minimal risk of data loss. This may act as a kind of backup copy as well. Last but not least this method simplifies the further evaluation of data because of a vast number of programming interfaces being able to communicate with database management systems. As a free and powerful solution the database management system MySQL was chosen for implementation. The necessary database structure and a parser created for this task which allows reading data from different sources and writing it into the prepared database will be presented. With this MySQL-database off-line analyses and display of weather and road traffic data can be done. It is possible to visualize different safety parameters like time-to-collision (TTC) or (compensated) individual braking time risk (CIBTR) together with velocity and traffic flow. The evaluation of the relation between traffic flow and different weather situations is possible. The MySQL-database is a useful instrument for researcher, consultant or motorway operator to analyze the traffic flow behavior