Analysis of SHRP2 Speeding Data: Methods Used to Conduct the Research

This report describes the methodologies and datasets used to prepare a set of data reductions that supported analyses of speeding behavior as discussed in the Findings Report from the same study (Richard, Lee, Brown, & Landgraf, 2019). Importantly, it is intended to be a guide that provides helpful insights for researchers to use when navigating the process of Strategic Highway Research Program 2 (SHRP2) data acquisition and processing. The report focuses primarily on the methods used to (1) obtain and process trip time-series data, (2) prepare data reductions to extract free-flow episodes (FFE)—driving in free-flow conditions where drivers have the opportunity to speed—and (3) extract speeding episodes (SE). The workflow for preparing the data reductions consisted of three components: data acquisition, data management, and data processing. Data acquisition consisted of identifying variables of interest, selecting variables, obtaining a data sharing agreement, preparing and submitting data requests, and retrieving data extracted by the SHRP2 data contractor (VTTI). Data management included tracking the status of each trip during processing; retrieving, manipulating, and storing data in a relational database management system; database administration; data security; and data quality management. Data processing included developing and implementing data processing software tools that cleaned the data; parsed them into Trips, FFEs, and SEs; and produced data reductions suitable for analysis. Lessons learned during the conduct of the research are provided. The report is available online at https://rosap.ntl.bts.gov/view/dot/44241