FHWA Reduced Intersection Data Set

Project Description The NDS Reduced Intersection data set was developed to complement the RID reduced intersection data set by leveraging existing SHRP2 NDS database assets. For a given intersection, map matching table information on unique sequences of links and the GPS-heading derived measures between sequential links were used to identify “intersection traversal” events including the associated maneuver being performed. This NDS reduced intersection dataset is a useful supplement for inclusion as part of InDepth NDS data requests when intersection traversals are of interest. The target users are researchers who are interested in studying driver behavior in a variety of intersection environments in order to develop models that can lead to better roadway design, enhanced traffic control and countermeasure approaches, and well-informed policy decisions. Data Request Scope The intersection trip summary includes the following variables: Basic Driver Information Anonymousparticipant_id – A numeric identifier assigned to a participant randomly during in-processing used in place of any other driver identity information Age Range – The age group corresponding to the driver’s age at study initiation Gender – The gender the participant Basic Vehicle Information Vehicle year – The year of manufacture for the vehicle Vehicle make – The make of the participant's study vehicle Vehicle model – The model of the participant’s study vehicle Basic Traversal Characteristics File_id – the unique numeric identifier assigned to a particular NDS trip Intersection_id – the unique variable string identifier retrieved from the RID and assigned to a reduced intersection node location IntersectionControlType – the intersection traffic control type, if available, as provided by RID source data Control Type for Intersection.Code Value: -1 Unknown 1 Controlled T Intersection 2 Signalized 3 Two-Way 4 Uncontrolled 5 Yield 6 All-Way 7 Roundabout Day_of_week – The day of the week when the trip started based on local time where 1=Sunday, 7=Saturday, and null is unknown Time_Bin_Hourly – Binned hourly for time of the day when the trip started based on local time. Where local time between 0 and 1 equals 1, local time between 1 and 2 equals 2, etc. Average_speed – the average vehicle network speed (km/h) during intersection traversal St_dev_speed – the standard deviation of vehicle network speed (km/h) during intersection traversal Max_speed – the maximum value of vehicle network speed (km/h) during intersection traversal Min_speed – the minimum value of vehicle network speed (km/h) during intersection traversal Time_5kmph_Under – the length of time, in milliseconds, when vehicle was less than five kilometers per hour (5km/h) during intersection traversal Average_Accel_X – the average longitudinal acceleration (g) during intersection traversal St_dev_Accel_X – the standard deviation of longitudinal acceleration (g) during intersection traversal Max_Accel_X – the maximum value of longitudinal acceleration (g) during intersection traversal Min_Accel_X – the minimum value of longitudinal acceleration (g) during intersection traversal Average_Accel_Y – the average lateral acceleration (g) during intersection traversal St_dev_Accel_Y – the standard deviation of lateral acceleration (g) during intersection traversal Max_Accel_Y – the maximum value of lateral acceleration (g) during intersection traversal Min_Accel_Y – the minimum value of lateral acceleration (g) during intersection traversal Full_Stop_Detected – Indicates if a full stop was detected at intersection approach, [“Yes”, “No”] = [1, 0]. A full stop was considered to be detected whenever the minimum speed during the traversal of the approaching link was 0 km/h, and such a speed observation was preceded by a measured deceleration of 0.05g or above. Manuever – type of intersection movement by selected trip (as either straight, left turn, or right turn) Data Specification Additional details can be found in the associated data dictionary. The resulting intersection maneuver matching data set consists of 42,275,375 intersection traversals across three defined turning maneuvers. A total of 223,621 hours of study time are included in these traversals.