RT Journal Article SR Electronic A1 Bureš, P. A1 Vlčinský, J. T1 Tracing Traffic Information Identity in Distribution Systems JF Transactions on Transport Sciences YR 2009 VO 2 IS 2 SP 60 OP 67 DO 10.5507/tots.2009.010 UL https://tots.upol.cz/artkey/tot-200902-0004.php AB Tracing messages and information passing through a distribution system is necessary for resolving problems and improving performance. This paper summarizes the requirements, analyzes the aspects, proposes a conceptual approach, gives an example of possible implementation, and summarizes the findings. A number of challenges are uncovered, for example prescribed identification schemes in the system; versioning; repetition of incoming and outgoing messages; multiple output channels; recycling of IDs; invalid messages, etc. The key requirement is to trace messages with information on the input and output of the distribution system by assigning the proper identifier information. Unfortunately, identification schemes are different as to the information provider, in the central data store and in each output channel; the solution must keep track of these differences, and therefore events affecting the assigned information identity must be documented. The same applies to transactions, affecting information existence, as is the case with information deletion due to expiration. A sample of possible implementation shows that linking information between different types of log records might be greatly simplified if processed information keeps track of the transaction which has imported the information into the system.