Freeway Gap Acceptance Behaviors Based on Vehicle Trajectory Analysis

Gap acceptance forms a significant component of lane change modeling. Most studies on gap acceptance focus either on intersections or on merging areas. There is relatively little research on gap acceptance behaviors during lane changes on freeways. This paper analyzed gap acceptance behaviors on freeway segments by conducting a detailed analysis of the vehicle trajectory data obtained through Next Generation SIMulation (NGSIM) program. The paper classified accepted gaps from the vehicle trajectory data into mandatory lane change (MLC) and discretionary lane change (DLC) gaps, and conducted a detailed regression analysis by studying 24 explanatory variables grouped into six categories. The analysis shows that MLC maneuvers require greater gaps than DLC maneuvers. Also, if multiple lanes need to be traversed for a MLC, drivers are more inclined to accept smaller gaps. Presence of Heavy vehicles as subject or lag vehicles also tend to increase accepted gaps for both MLC and DLC maneuvers, while front and lead vehicle types do not have significant effect. Regression analysis revealed that the variance of observed variables, including MLC-specific variables, vehicle types, speed, relative speed, acceleration, and relative acceleration, can explain the variance of accepted gaps about 49.5% and 38.9% for MLC and DLC, respectively. This suggests that some other unobserved factors, such as gender, age, trip purpose, etc., may also play a role in gap acceptance when conducting lane changes on freeways. Overall, this paper enriches the understanding of gap acceptance behaviors when driving on freeways.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Zhang, Lin
  • Kovvali, Vijay Gopal
• Conference:
  • Transportation Research Board 86th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2007-1-21 to 2007-1-25
• Date: 2007

Language

• English

Media Info

• Media Type: CD-ROM
• Features: Figures; References; Tables;
• Pagination: 20p
• Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

• TRT Terms: Behavior; Freeway operations; Freeways; Gap acceptance; Lane changing; Operations; Traffic flow; Traffic speed; Trip purpose; Vehicle trajectories
• Identifier Terms: Next Generation Simulation program
• Uncontrolled Terms: Vehicle type
• Subject Areas: Administration and Management; Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors; I72: Traffic and Transport Planning; I73: Traffic Control;

Filing Info

• Accession Number: 01049565
• Record Type: Publication
• Report/Paper Numbers: 07-2739
• Files: TRIS, TRB
• Created Date: May 21 2007 1:18PM