Quality Assurance and Quality Control Processes for a Large-Scale Bicycle and Pedestrian Volume Data Program

Abstract

Phase 1 of North Carolina’s Non-Motorized Volume Data Program (NMVDP) was conducted in the North Carolina Department of Transportation Divisions 7 and 9 in the Triad–Piedmont region of North Carolina. Continuous count stations (CCSs) were installed to monitor bicyclist and pedestrian traffic at 12 locations and began collecting data in late 2014. These stations covered a mix of sites across different land uses, travel patterns, and volume groups. Sites performed automated detection of pedestrians on sidewalks, bicycles and pedestrians on shared-use paths, bicycles in bicycle lanes, bicycles on sidewalks, and bicycles in mixed traffic. This paper summarizes the programmatic elements developed and implemented to select, install, and ensure high data quality for the 12 CCSs. These elements include agency coordination, site selection, equipment procurement and setup, equipment validation, equipment maintenance, data handling, quality assurance and quality control checks, and data reporting and analysis. After piloting this program in one region, the research team identified several changes to test when the NMVDP was expanded to a new region of the state to improve the quality of data collected: conduct weekly inspections of the data and perform validation to promptly identify maintenance issues, investigate the development of hourly data checks to implement, use a simpler interquartile range check, and consider developing automation to check data.