National Performance Management Research Dataset (NPMRDS) - Speed Validation for Traffic Performance Measures

2017Final Report Oct 2015 - Oct 2017PDFTech ReportFHWA-OK-17-02ODOT SPR Item Number 2300 (16-01)Performance measurementSpeed dataTraffic congestionTraffic dataTraffic flowTraffic surveillanceTravel timeValidationMachine learningData analysisIntelligent transportation systemsAdvanced traffic management systemsITSTraffic AnalyticsData AnalyticsNPMRDSUnited StatesOklahomaOklahoma. Department of TransportationRefai, Hazem H.Bitar, NaimKaleia, Muhanad ShabUniversity of OklahomaOklahoma. Department of Transportation. Office of Research and ImplementationUS Transportation CollectionThis report presents research detailing the use of the first version of the National Performance Management Research Data Set (NPMRDS v.1) comprised of highway vehicle travel times used for computing performance measurements in the state of Oklahoma. Data extraction, preprocessing, and statistical analysis were performed on the dataset and a comprehensive study of dataset characteristics, influencing variables, outliers and anomalies was carried out. In addition, a study on filtering and removing speed data outliers across multiple road segments is developed, and a comparative analysis of raw baseline speed data and cleansed data is performed. A method for improved congestion detection is investigated and developed. Identification and a computational comparison analysis of travel time reliability performance metrics for both raw and cleansed datasets is shown. An outlier removal framework is formulated, and a cleansed and complete version of NPMRDS v.1 is generated. Finally, a validation analysis on the cleansed dataset is presented. In the end, research affirms that understanding domain specific characteristics is vital for filtering data outliers and anomalies of this dataset, which in turn is key for calculating accurate performance measurements. Thus, careful consideration for outlier removal must be taken into account when computing travel time reliability metrics using the NPMRDS.81