Patent ID: 7857213

Claim:
A method for access control to at least two groups of transport facilities, each group having a separate database, each transport facility including at least one access control device having at least one read/write device for reading data carriers, the read/write devices of each said group being networked with the respective database, the data carrier having an identification number, and application data stored on the data carrier, including the steps of: providing the data carrier with a transaction counter for storing a transaction number which is changed upon a change of the application data, storing the application data, the identification number and the transaction number of the transaction counter of the data carrier in the database of the group of the transport facilities that the user goes to initially, upon access to a transport facility of said group, reading the identification number and the transaction number from the transaction counter of the data carrier with the read/write device, in case of no match of both the identification number read out from the data carrier and the transaction number read out from the transaction counter of the data carrier with the identification number and the transaction number stored in the database, retrieving the application data from the data carrier, and in case of a match of both the identification number and the transaction number, along with the application data stored in the database indicating a valid access authorization, operating the particular access control device to provide access without reading the application data from the data carrier, wherein upon changing from one group to another group of transport facilities, the read/write device of the transport facility of the another group to which the user has changed, reading the identification number and the transaction number of the transaction counter, when the identification number or the transaction number does not match, reading the application data from the data carrier, and providing access with the access control device, so long as the application data includes a valid access authorization.