01099315

Component

https://doi.org/10.3141/2088-10

http://scholar.google.com...ting&publication_year=2008

The Next Generation Simulation (NGSIM) trajectory data sets provide longitudinal and lateral positional information for all vehicles in certain spatiotemporal regions. Velocity and acceleration information cannot be extracted directly because the noise in the NGSIM positional information is greatly increased by the necessary numerical differentiations. A smoothing algorithm is proposed for positions, velocities, and accelerations that can also be applied near the boundaries. The smoothing time interval is estimated on the basis of velocity time series and the variance of the processed acceleration time series. The velocity information obtained in this way is then applied to calculate the density function of the two-dimensional distribution of velocity and inverse distance and the density of the distribution corresponding to the “microscopic” fundamental diagram. It is also used to calculate the distributions of time gaps and times to collision, conditioned to several ranges of velocities and velocity differences. By simulating virtual stationary detectors, it is shown that the probability for critical values of the times to collision is greatly underestimated when estimated from single-vehicle data of stationary detectors. Finally, the lane-changing process is investigated, and a quantitative criterion is formulated for the duration of lane changes that is based on the trajectory density in normalized coordinates. There is a noisy but significant velocity advantage in favor of the targeted lane that decreases immediately before the change due to anticipatory accelerations.

01121596

English

pp 90-101

2008

Transportation Research Record: Journal of the Transportation Research Board

9780309126038

Print

Figures (8) ; References (21) ; Tables (1)

Acceleration (Mechanics); Algorithms; Interference; Lane changing; Traffic flow; Traffic simulation; Vehicle trajectories; Velocity

Next Generation Simulation program

Data filtering; Data smoothing

Highways; Operations and Traffic Management; I71: Traffic Theory

TRIS, TRB, ATRI

Jan 29 2008 4:25PM

• Asymptotic Stability and Vehicle Safety in Dynamic Car-Following Platoon
• Calibrating Car-Following Models by Using Trajectory Data: Methodological Study
• Comparison of Simulation-Based and Model-Based Calibrations of Traffic-Flow Microsimulation Models
• Comparisons of Speed–Spacing Relations Under General Car Following Versus Lane Changing
• Desired Speed Distributions on Two-Lane Highways Under Various Conditions
• Empirical Measurement of Freeway Oscillation Characteristics: An International Comparison
• Empirical Study of Behavioral Theory of Traffic Flow: Analysis of Recurrent Bottleneck
• Estimating Individual Speed–Spacing Relationship and Assessing Ability of Newell’s Car-Following Model to Reproduce Trajectories
• Evaluation of Corridor Traffic Management and Planning Strategies That Use Microsimulation: A Case Study
• FASTLANE: New Multiclass First-Order Traffic Flow Model
• From Existing Accident-Free Car-Following Models to Colliding Vehicles: Exploration and Assessment
• Lane Selection Model for Urban Intersections
• Macroscopic Modeling Framework Unifying Kinematic Wave Modeling and Three-Phase Traffic Theory
• Microsimulation Calibration Using Speed–Flow Relationships
• Modeling Driver Behavior as Sequential Risk-Taking Task
• New Behavioral Model for Microscopic Freeway Traffic-Flow Simulation
• On-Ramp Metering Based on Three-Phase Traffic Theory Downstream Off-Ramp and Upstream On-Ramp Bottlenecks
• Oversaturated Freeway Flow Algorithm for Use in Next Generation Simulation
• The Less-Than-Perfect Driver: A Model of Collision-Inclusive Car-Following Behavior
• Use of Microsimulation to Model Day-to-Day Variability of Intersection Performance
• Validity of Trajectory-Based Calibration Approach of Car-Following Models in Presence of Measurement Errors
• What Do Different Traffic Flow Models Mean for System-Optimal Dynamic Traffic Assignment in a Many-to-One Network?