In the drive towards truly automated driving infrastructure data will play a substantial role, as it enhances the event horizon of the autonomous vehicle and enables the road operator to communicate strategic routing information. As infrastructure data is basically an aggregation of large data source systems, the guaranteed latency with which relevant information can be conveyed to the vehicle poses a challenge. This paper breaks up the downstream data chain from the infrastructure to the vehicle into its generic building blocks and focusses on the data throughput rate of the infrastructure database element. The achievable throughput rates are determined experimentally in a real life productive system during standard operation, the traffic information system of Austrian highway operator ASFINAG. The throughput rates through the main data gates have been made configurable and the timestamps for data passing through the individual software modules are recorded. Measurement results for the configuration with the highest throughput rate show a mean latency of 2 to 6 seconds for traffic messages from infrastructure into the vehicle, excluding the time for event detection. The concept will be expanded to eventually determine and monitor latency through all building blocks of the data chain.