{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T18:04:00Z","timestamp":1789581840874,"version":"build-2803163510"},"reference-count":34,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T00:00:00Z","timestamp":1789516800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Saudi Arabia\u2019s rural highway network experiences a high number of severe run-off-road and rollover crashes, yet evidence-based, locally validated roadside clear-zone design guidance remains limited. This study investigates how roadside clear-zone characteristics influence the occurrence and severity of these crashes by integrating statistical analysis of in-depth investigations of multi-fatality crash data with high-fidelity vehicle simulations. An in-depth dataset of 127 multi-fatality crashes (2020\u20132022) from the National Road Safety Centre was analyzed using binary logistic regression to identify key predictors of run-off-road severity. The final model retained three significant variables: Vehicle Type (odds ratio OR = 0.56 per class increase, p\u2009&lt;\u20090.001), indicating that heavier vehicle categories diminish rollover risk; Posted Speed (OR = 1.017 per km\/h increase, p\u2009=\u20090.032), reflecting elevated crash likelihood at higher speed limits; and Steep Slope (V:H\u2009\u2265\u20091:4) (OR = 2.73, p\u2009=\u20090.054), underscoring the destabilizing effect of steep embankments on vehicle stability. Descriptive statistics revealed an average of 3.59 fatalities and 2.80 injuries per crash, with single-vehicle incidents comprising 78% of the sample. Complementary finite-element simulations using AnalyzerPro examined sixteen scenarios that varied clear-zone width (3\u20137 m), embankment gradient (1:2.5 vs. 1:10), and soil compaction at speeds of 100 km\/h and 140 km\/h. Widening the clear zone from 3 m to 7 m reduced rollover probability by approximately 45%, while fully compacted embankments and slopes consistently prevented rollovers across all vehicle classes and speed profiles. Steeper slopes markedly increased rollover propensity relative to gentler grades. These findings provide robust, evidence-based guidance for updating roadside design standards\u2014emphasizing clear-zone widening, soil compaction protocols, and slope moderation\u2014to enhance safety on Saudi Arabia\u2019s rural road network.<\/jats:p>","DOI":"10.1371\/journal.pone.0357284","type":"journal-article","created":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T17:37:55Z","timestamp":1789580275000},"page":"e0357284","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Evidence-based roadside clear-zone design for mitigating run-off-road and rollover crashes on rural highways in Saudi Arabia"],"prefix":"10.1371","volume":"21","author":[{"given":"Turki A.","family":"Alamoudi","sequence":"first","affiliation":[{"name":"King Saud University","place":["Riyadh, Saudi Arabia"],"department":["Civil Engineering Department"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-9937-2794","authenticated-orcid":true,"given":"Saif A.","family":"Alarifi","sequence":"additional","affiliation":[{"name":"King Saud University","place":["Riyadh, Saudi Arabia"],"department":["Civil Engineering Department"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,9,16]]},"reference":[{"key":"pone.0357284.ref001","author":"NTP (National Transformation Program)","year":"2018"},{"key":"pone.0357284.ref002","article-title":"D05: Summary of European design guidelines for roadside infrastructure.","volume-title":"RISER - Roadside infrastructure for safer European roads","author":"G Dupre","year":"2006"},{"key":"pone.0357284.ref003","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1177\/0361198106196100109","article-title":"Design of safe urban roadsides: an empirical analysis","volume":"1961","author":"E Dumbaugh","year":"2006","journal-title":"Transp Res Rec"},{"key":"pone.0357284.ref004","doi-asserted-by":"crossref","first-page":"156","DOI":"10.3141\/1897-20","article-title":"Marginal impacts of design, traffic, weather, and related interactions on roadside crashes","volume":"1897","author":"VN Shankar","year":"2004","journal-title":"Transp Res Rec"},{"key":"pone.0357284.ref005","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/j.sbspro.2012.09.876","article-title":"Improving roadside design to forgive human errors","volume":"53","author":"F La Torre","year":"2012","journal-title":"Procedia Soc Behav Sci"},{"key":"pone.0357284.ref006","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.aap.2018.08.008","article-title":"Improving roadside design policies for safety enhancement using hazard-based duration modeling","volume":"120","author":"C Roque","year":"2018","journal-title":"Accid Anal Prev"},{"key":"pone.0357284.ref007","doi-asserted-by":"crossref","DOI":"10.1007\/978-3-030-76505-7_36","article-title":"Rural road design according to the safe system approach.","author":"H Stigson","year":"2023","journal-title":"The vision zero handbook. 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