The MIRE MIS concept offers many potential benefits to agencies safety programs. The MIS brings together data from many sources. Each of these sources pertain to safety issues and can provide valuable information in determining where safety can be improved and what measures may be most effective.
In order for the MIRE MIS to be most functional, the data in the system need to be of a high quality (better data = better analysis results). But, the data also need to be well structured with a consistent data structure and referencing system from year to year. The first decisions made in a full implementation of a MIRE MIS will be which data to include in the system and how to connect the MIS to the source data. One approach is to export data from the source, then import to MIS and update the data on a regular schedule. If the data structure closely matches the structure of the MIS, an agency can largely automate importing and updating the data to keep the system up to date.
While developing the MIRE MIS prototype with data from NHDOT, two issues became clear:
1) The structure of the data did not match the MIRE structure, so data needed to be transformed to the MIS structure on import; and
2) The structure and referencing system of the data collected by NHDOT changed from year to year.
One of the keys to the success of an MIS is the ability to correlate data from disparate systems to the relevant roadway elements. NHDOT updates its roadway inventory annually to reflect changes (new roads, changed intersections, changed alignments, etc.). NHDOT assigns each roadway segment a unique identifier within that inventory, but these identifiers are not consistent from year to year. This limits the ability to correlate data between the sources in the MIS. The project team added the data in the NHDOT MIRE MIS prototype as a snapshot to try to maintain internal consistency between the data sets.
A full MIRE MIS implementation will contain data collected over time and will need a way to compare data from different collection periods. This way the system can provide analysis of conditions before and after improvements are made, and will allow comparative analysis of data quality. This underscores the importance of a consistent data structure and referencing system that can be used in the collection of safety data.
The MIRE MIS concept discusses several aspects of the system that could tie into a GIS to aid in data entry, querying, and spatial analysis. GIS can also be used to address some of the key concerns of data structure and spatial references changing over time. A GIS can apply an absolute spatial reference and provide spatial analysis tools for an alternate way to match data points from different systems, whether these represent the same data collected at different times (e.g., roadway segments from different years), or they represent different data with independent referencing systems (e.g., crash data and bridge data). Adding a GIS component does introduce platform dependencies that may differ from State to State, but regardless of the platform, tying the data into a GIS is an important part of the MIRE MIS.
Based on the work completed to date, further research is needed to integrate the MIRE MIS data structure to the geographic/spatial roadway and traffic segments. Relationship classes between the database attributes and the corresponding geometric features need to be explored in order for spatial analyses to be performed on the information system as whole. It appears that MIRE MIS could be advanced by integrating additional core principles of GIS into the data management scheme. For instance, in addition to tabular relationships, GIS heavily relies on spatial relationships and topological rules to represent data quality and to promote data analysis.
Integrating quality roadway and traffic data with crash data helps agencies make better decisions and more effective use of limited funds to improve safety. The overall MIRE MIS effort provides lessons on how to collect, integrate, manage, and measure data for improved safety decision- making. Even though there is some additional research that is needed, this effort to develop and test helps bring State and local agencies one step closer to realizing the benefits of establishing an MIS to support their own safety programs.