Overview

This repository provides the data and code for assessing collision risk for tractor-semitrailer vehicles using two-dimensional time-to-collision.

Data Description

The Simulation data folder contains 30 .csv files, with 15 rear-end and 15 sideswipe collision scenarios. The files are named, for example, vehicle_dataLateral_11_c0. Here:

• Lateral denotes a sideswipe scenario,
• 11 is the trailer length in meters,
• c0 is the case number.

Simulator Data Columns

Each simulation file contains the following columns, with each row representing a snapshot at a given time step:

Column	Description
x1, y1	Global coordinates of the tractor
x2, y2	Global coordinates of the semitrailer
x3, y3	Global coordinates of the car
vLx1, vLy1	Local frame velocities of the tractor
vGx1, vGy1	Global frame velocities of the tractor
vLx2, vLy2	Local frame velocities of the semitrailer
vGx2, vGy2	Global frame velocities of the semitrailer
vLx3, vLy3	Local frame velocities of the car
vGx3, vGy3	Global frame velocities of the car
yaw1, pitch1, roll1	Orientation angles of the tractor
yaw2, pitch2, roll2	Orientation angles of the semitrailer
yaw3, pitch3, roll3	Orientation angles of the car
delta	Steering input of the tractor-semitrailer

Code Description

The files TTCv2_predict_from_scenarios and TTCv3_predict_from_scenarios read all scenarios and output time-to-collision estimates at 1, 1.38, and 2 seconds for both versions for each scenario.

Rear-end collision

SideSwipe collision

Citation

If you use this repository in your research, please cite:

@article{behera2025improved,
title={A two-dimensional time-to-collision for articulated vehicles: predicting sideswipe and rear-end collisions},
author={Behera, Abhijeet and Kharrazi, Sogol and Frisk, Erik and Aramrattana, Maytheewat},
journal={arXiv preprint arXiv:2507.04184},
year={2025}
}