The data used in a TIM performance measurement database does not necessarily only need to be created from scratch in the new database. If an agency has already begun collecting TIM performance data, or if data are available from another database (e.g., police CAD system), these data could be extracted, transformed, and loaded into the TIM performance measurement database even if the data are not organized or structured exactly like the TIM model database provided here. There are many different ways in which data that previously have been collected could be imported into the TIM performance measurement database. For example, the user could take previously collected data in an Excel spreadsheet and map/convert the data contained in the file to take the form of one or more of the TIM performance measurement database tables. Once the data are in the form of the TIM performance measurement database table, the user could import that data directly into the database using a standard import function that most database management systems have. If the data exist in a format that is not easily mapped and converted into the form of the TIM database tables, a custom program could be written in any language to further process the data in the current form and write it out either directly to the database or other easily-imported format using the database management system. Once the data extraction, mapping, and loading process(es) have been developed, these processes can be used again and again to import new data sets using the same format, thus allowing instant access to past data in the TIM performance measurement database.
The analysis of existing data, even if there are missing data elements within the database, could help an agency get an idea of past/current performance and a base on which to build a TIM performance measurement database that includes more data elements. Agencies could also use the knowledge gained on TIM performance as a baseline for setting performance targets as they move forward with the TIM performance measurement program.
In some cases, an agency may have (or have access to) an existing database that could provide some of the data elements for the incidents. Therefore, for each incident, the agency would only need to input some of the data elements, while the others could be added through uploading from the other database(s). For example, the police department likely has much of the incident information from crash/incident reports. Working together, the agencies could build a process of sharing and merging the data to populate as many data elements in the model TIM performance measurement database as possible. As was previously discussed, FAST reviews archived snapshots of incidents and the surrounding roadways prior to reporting the 30-60-90 TIM performance to the Nevada DOT. This is an excellent example of the use of existing/archived data for further populating the TIM performance database.
It should be noted that data exchange and/or transformation from one system (database) to another can be a complex undertaking and needs careful planning and oversight. As referenced earlier in the guidance, a multi-agency task force can be used to examine the data availability, definitions, and sharing capability and to develop the functional requirements for the data exchange that must be implemented by information technology (IT) staff.