Determination of the Parameters Effective in Traffic Accidents with Fixed Objects by Factorial Design Method
archive: archived pipeline: cataloged verified
Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)
Summary
This study investigates the factors influencing traffic accidents involving collisions with fixed objects, aiming to identify which parameters have the most significant singular and interactive effects on accident frequency. The research is motivated by the high socio-economic costs of traffic accidents in Turkey, where road transport dominates freight and passenger movement. While various accident prediction models exist in literature, such as those by Smeed, Andreassen, and Zegeer, there is a need to rigorously determine the sensitivity of specific geometric and traffic variables within these models to inform safer road design and policy. The authors employ a factorial design method, a type of sensitivity analysis developed by Box et al., to evaluate a five-variable accident model. Unlike traditional sensitivity analyses that alter one parameter at a time, this method allows for the simultaneous assessment of individual parameter effects and their complex interactions. The model analyzed is defined by the equation $CO = 0.00002 \times ADT \times W^{0.88} \times C^{1.10} \times D^{0.86} \times T^{1.2}$, where the variables are Average Daily Traffic (ADT), Lane Width (W), Roadside Area (C), Distance of the fixed object from the shoulder (D), and Terrain Condition (T). The study utilizes a two-level factorial design, assigning minimum and maximum values to each parameter (e.g., ADT ranging from 500 to 10,000 vehicles/day; W from 8 to 12 feet). The effects of these parameters and their interactions were calculated and analyzed using normal probability plots and categorized by importance based on absolute standard deviations, following the methodology of Henderson-Sellers. The results identify the most critical factors affecting fixed-object accidents. Among singular parameters, Average Daily Traffic (ADT) is determined to be the most influential, followed by the distance of the fixed object from the shoulder (D) and lane width (W). Specifically, ADT is categorized as having a primary effect ($|4\sigma|$), while D and W are secondary ($|3\sigma|$ and $|\sigma|$ respectively). Regarding multiple interactions, the study finds that the combined effects of lane width and distance from the shoulder (W-D) and the combined effects of average daily traffic and distance from the shoulder (ADT-D) are the most significant interactive factors. These interactions deviate significantly from the normal distribution line in the probability plot, indicating their substantial impact on accident occurrence compared to other parameter combinations. The significance of this work lies in its application of factorial design to traffic safety modeling, providing a structured approach to prioritize road design improvements. By identifying ADT, shoulder distance, and lane width as the primary drivers of fixed-object accidents, the study offers evidence-based recommendations for engineers and policymakers. It suggests that interventions focusing on managing traffic volume, increasing the clearance distance of fixed objects from the shoulder, and optimizing lane widths are likely to yield the greatest reductions in accident frequency. This methodological approach allows for efficient identification of key risk factors without requiring exhaustive experimental trials, contributing to more effective and cost-efficient traffic safety strategies.
Provenance
The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.
| Stage | Outcome | Tool | Model | Prompt | Attempts | Completed |
|---|---|---|---|---|---|---|
| discover | success | Crossref | — | — | 1 | 2026-06-25 |
| archive | success | unpaywall | — | — | 2 | 2026-06-26 |
| extract | success | cached | — | — | 2 | 2026-06-26 |
| clean | success | clean | — | — | 1 | 2026-06-26 |
| chunk | success | chunk | — | — | 1 | 2026-06-26 |
| embed | success | embed | Qwen/Qwen3-Embedding-8B | — | 1 | 2026-06-26 |
| enrich | success | openalex | — | — | 1 | 2026-06-26 |
| promote | success | — | — | — | 1 | 2026-06-25 |
| summarize | success | llm | qwen3.6-27b-prismaquant | summ-v5 | 1 | 2026-06-26 |
| tag | success | vector_similarity | — | — | 6 | 2026-06-26 |
| verify | success | — | — | — | 1 | 2026-06-26 |
Summary generated by qwen3.6-27b-prismaquant on 2026-06-26; verification: verified.
Topics
Ranked by relevance to this paper. Hover a topic for its definition.
Information type
What kind of knowledge this paper contributes, grouped by family — independent of topic (what it is about) and method (how it was studied).
- Empirical Findings: crash risk outcomes