Developing speed‐related safety performance indicators from floating car data

In the road traffic safety domain there is a need for using proactive (non-crash-based) indicators, known as performance indicators (SPIs). Traffic speed based on big data (floating car [FCD]) could help develop network-wide SPIs, but related knowledge and experience are insufficient so far. The authors attempted to fill this gap by nationwide Italian FCD speed-related SPIs validating their relationship crashes see potential explanatory value. calculated coefficient of variance (CV), congestion index (CI), number incidents candidate SPIs. For validation, used linear correlation, crash frequency model, ranking consistency. Incidents turned out be best SPI, especially motorways.