Table 3 Objective driving behavior variables and definitions used in the Longitudinal Research on Aging Drivers (LongROAD) study
From: Longitudinal Research on Aging Drivers (LongROAD): study design and methods
Name | Definition |
|---|---|
Year | Calendar year |
Month | Calendar month |
Subject no. | Participant identification number |
Days driving | Total number of days in month with at least one trip |
Trips | Total number of trips in month |
Miles | Total number of miles driven in month |
Miles per trip | Total number of miles driven in month divided by total number of trips in month |
Total trip minutes | Total minutes of driving in month |
Minutes per trip | Total driving minutes in month divided by total number of trips in month |
Trip chains | Number of trip chains in month (Note: chain is a series of trips starting and ending at home) |
Minutes per chain | Total driving minutes for chains divided by the number of trip chains in month |
Miles per chain | Total miles of chains in month divided by total number of trips chains in month |
No. trips at night | Number of trips during which at least 80% of trip was during nighttime in month (Nighttime was defined as civil twilight or a solar angle greater than 96 deg) |
% trips at night | Percent of all trips at nighttime |
No. trips during day | Number of trips in month not classified as nighttime |
% trips during day | Percent of trips in month not classified as nighttime |
No. trips in AM peak | Number of trips in month during 7–9 AM on weekdays |
% trips in AM peak | Percent of trips in month during 7–9 AM on weekdays |
No. trips in PM peak | Number of trips in month during 4–6 PM on weekdays |
% trips in PM peak | Percent of trips in month during 4–6 PM on weekdays |
No. trips on high speed roads | Number of trips in month where 20% of distance travelled was at a speed of 60 MPH or greater |
% trip on high speed roads | Percent of trips in month where 20% of distance travelled was at a speed of 60 MPH or greater |
No. trips <15 miles of home | Number of trips traveled in month within 15 miles of home |
% trips <15 miles of home | Percent of trips traveled in month within 15 miles of home |
No. trips <25 miles of home | Number of trips traveled in month within 25 miles of home |
% trips <25 miles of home | Percent of trips traveled in month within 25 miles of home |
No. left turns | Number of left turns made in month |
No. right turns | Number of right turns made in month |
Right to left turn ratio | Ratio of all right-hand to left-hand turning events for a driver in a month |
No. high deceleration events | Number of events with deceleration ≥0.4 g in a month (hard braking, near crash) |
No. speeding events | Number speeding events in month (speed ≥80 MPH sustained for at least 8 s) |