Related Experiment Video
Updated: Dec 13, 2025

Evaluating the Effect of Roadside Parking on a Dual-Direction Urban Street
Published on: January 20, 2023
A Bayesian modeling framework for crash severity effects of active traffic management systems
Zulqarnain H Khattak1, Michael D Fontaine2
1Oak Ridge National Laboratory, Oak Ridge, TN 37830, United States.
Active traffic management (ATM) systems reduce crash severity. Deployments with hard shoulder running (HSR) decreased severe and minor injury likelihoods, while ATM without HSR also showed significant reductions in injury severity.
Area of Science:
- Transportation Engineering
- Traffic Safety
- Road Infrastructure Management
Background:
- Active Traffic Management (ATM) systems dynamically manage congestion using real-time data.
- Previous research indicates some safety benefits of ATM, but its effect on crash injury severity remains unclear.
Purpose of the Study:
- To quantify the impact of Active Traffic Management (ATM) deployment on road crash injury severity.
- To differentiate the effects of ATM with and without hard shoulder running (HSR).
Main Methods:
- Utilized full Bayesian mixed logit models to analyze crash data.
- Quantified the marginal effects of ATM deployment on different injury severity levels.
- Validated model performance using forecast error and temporal transferability.
Main Results:
- ATM deployment was associated with reduced crash severities.
- ATM with hard shoulder running (HSR) reduced severe/moderate injury likelihood by 15.9% and minor injury by 10.1%.
- ATM without HSR reduced severe/moderate injury likelihood by 12.4% and minor injury by 8.33%.
Conclusions:
- ATM systems demonstrably lower injury severity in freeway crashes.
- HSR is a key component in maximizing the injury reduction benefits of ATM.
- Findings provide crucial insights for enhancing freeway safety at critical locations.
Related Concept Videos
Mechanistic Models: Compartment Models in Individual and Population Analysis
Design Example: Analyzing Capacity Contours for Flood Risk Assessment
Model Approaches for Pharmacokinetic Data: Distributed Parameter Models
The distributed parameter models are specifically designed to account for variations and differences in some drug classes. This model is particularly useful for assessing regional concentrations of anticancer or...
Response Surface Methodology
The process of RSM involves several key steps:
Mechanistic Models: Overview of Compartment Models
Parametric Survival Analysis: Weibull and Exponential Methods
Weibull Distribution
The Weibull distribution is a flexible model used in parametric survival analysis. It can handle both increasing and decreasing hazard rates, depending on its shape parameter...

