{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,2]],"date-time":"2026-03-02T20:29:07Z","timestamp":1772483347251,"version":"3.50.1"},"reference-count":41,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2019,6,6]],"date-time":"2019-06-06T00:00:00Z","timestamp":1559779200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/Multi\/04427\/2013"],"award-info":[{"award-number":["UID\/Multi\/04427\/2013"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/Multi\/04423\/2019"],"award-info":[{"award-number":["UID\/Multi\/04423\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sustainability"],"abstract":"<jats:p>Most previous studies show that inclement weather increases the risk of road users being involved in a traffic crash. However, some authors have demonstrated a little or even an opposite effect, observed both on crash frequency and severity. In urban roads, where a greater number of conflict points and heavier traffic represent a higher exposure to risk, the potential increase of crash risk caused by adverse weather deserves a special attention. This study investigates the impact of meteorological conditions on the frequency of road crashes in urban environment, using the city of Porto, Portugal as a case study. The weather effects were analyzed for different types of crashes: single-vehicle, multi-vehicle, property-damage-only, and injury crashes. The methodology is based on negative binomial and Poisson models with random parameters, considering the influence of daily precipitation and mean temperature, as well as the lagged effects of the precipitation accumulated during the previous month. The results show that rainy days are more prone to the occurrence of road crashes, although the past precipitation may attenuate such effect. Temperatures below 10 \u00b0C are associated with higher crash frequencies, complying with the impacts of precipitation in the context of the Portuguese climate characteristics.<\/jats:p>","DOI":"10.3390\/su11113176","type":"journal-article","created":{"date-parts":[[2019,6,6]],"date-time":"2019-06-06T03:38:01Z","timestamp":1559792281000},"page":"3176","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Urban Road Crashes and Weather Conditions: Untangling the Effects"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7614-7605","authenticated-orcid":false,"given":"Ant\u00f3nio","family":"Lobo","sequence":"first","affiliation":[{"name":"Faculty of Engineering of the University of Porto, Research Centre for Territory, Transports and Environment, 4200-465 Porto, Portugal"}]},{"given":"Sara","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Faculty of Engineering of the University of Porto, Research Centre for Territory, Transports and Environment, 4200-465 Porto, Portugal"}]},{"given":"Isabel","family":"Iglesias","sequence":"additional","affiliation":[{"name":"Interdisciplinary Centre of Marine and Environmental Research of the University of Porto, 4450-208 Matosinhos, Portugal"}]},{"given":"Ant\u00f3nio","family":"Couto","sequence":"additional","affiliation":[{"name":"Faculty of Engineering of the University of Porto, Research Centre for Territory, Transports and Environment, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,6,6]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2013). Global Status Report on Road Safety 2013: Supporting a Decade of Action, World Health Organization."},{"key":"ref_2","unstructured":"European Commission (2008). White Paper on Transport\u2014Roadmap to a Single European Transport Area, Publications Office of the European Union."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1016\/j.aap.2014.06.017","article-title":"A review of the effect of traffic and weather characteristics on road safety","volume":"72","author":"Theofilatos","year":"2014","journal-title":"Accid. Anal. Prev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1016\/S0001-4575(03)00085-X","article-title":"The mixed effects of precipitation on traffic crashes","volume":"36","author":"Eisenberg","year":"2004","journal-title":"Accid. Anal. Prev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1180","DOI":"10.1016\/j.aap.2008.01.001","article-title":"Studying the effect of weather conditions on daily crash counts using a discrete time-series model","volume":"40","author":"Brijs","year":"2008","journal-title":"Accid. Anal. Prev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1016\/j.aap.2013.03.006","article-title":"Explaining the road accident risk: Weather effects","volume":"60","author":"Debbarh","year":"2013","journal-title":"Accid. Anal. Prev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/S0022-4375(98)00051-6","article-title":"The Relationship Between Road Accident Severity and Recorded Weather","volume":"29","author":"Edwards","year":"1998","journal-title":"J. Saf. Res."},{"key":"ref_8","unstructured":"Santos, F.D., Forbes, K., and Moita, R. (2002). 20th Century Portuguese Climate and Climate Scenarios. Climate Change in Portugal: Scenarios, Impacts and Adaptation Measures, Gradiva."},{"key":"ref_9","first-page":"96","article-title":"Let\u2019s Talk about the Weather\u2014Interpretation of Short Term Changes in Road Accident Outcomes","volume":"14","author":"Martensen","year":"2016","journal-title":"Transp. Res. Proc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"481","DOI":"10.1007\/BF00140357","article-title":"Effects of summer precipitation on urban transportation","volume":"32","author":"Changnon","year":"1996","journal-title":"Clim. Chang."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.trd.2008.12.004","article-title":"The impact of climate change and weather on transport: An overview of empirical findings","volume":"14","author":"Koetse","year":"2009","journal-title":"Transp. Res. D Transp. Environ."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.tbs.2013.10.005","article-title":"The influence of rainfall on road accidents in urban areas: A weather radar approach","volume":"1","author":"Jaroszweski","year":"2014","journal-title":"Travel Behav. Soc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.jsr.2013.04.007","article-title":"Identifying crash-prone traffic conditions under different weather on freeways","volume":"46","author":"Xu","year":"2013","journal-title":"J. Saf. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1016\/j.aap.2005.06.025","article-title":"Road accidents and rainfall in a large Australian city","volume":"38","author":"Keay","year":"2006","journal-title":"Accid. Anal. Prev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1175\/WCAS-D-16-0035.1","article-title":"Effects of Rainfall on Vehicle Crashes in Six U.S. States","volume":"9","author":"Black","year":"2017","journal-title":"Weather Clim. Soc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/j.aap.2018.10.014","article-title":"Accident risk of road and weather conditions on different road types","volume":"122","author":"Malin","year":"2019","journal-title":"Accid. Anal. Prev."},{"key":"ref_17","first-page":"48","article-title":"The Palm distribution of traffic conditions and its application to accident risk assessment","volume":"12","author":"Norros","year":"2016","journal-title":"Anal. Methods Accid. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1016\/0001-4575(95)00038-0","article-title":"Daily fluctuations in Honolulu motor vehicle accidents","volume":"27","author":"Levine","year":"1995","journal-title":"Accid. Anal. Prev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0001-4575(94)E0023-E","article-title":"Measuring the contribution of randomness, exposure, weather and daylight to the variation in road accidents","volume":"27","author":"Ifver","year":"1995","journal-title":"Accid. Anal. Prev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1016\/j.jsr.2005.06.013","article-title":"Data mining of tree-based models to analyze freeway accident frequency","volume":"36","author":"Chang","year":"2005","journal-title":"J. Saf. Res."},{"key":"ref_21","unstructured":"Yannis, G., and Karlaftis, M.G. (2010, January 10\u201314). Weather Effects on Daily Traffic Accidents and Fatalities: A Time Series Count Data Approach. Proceedings of the Transportation Research Board 89th Annual Meeting Compendium of Papers, Washington, DC, USA."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1016\/j.aap.2006.10.012","article-title":"A crash-prediction model for multilane roads","volume":"39","author":"Caliendo","year":"2007","journal-title":"Accid. Anal. Prev."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/j.aap.2009.07.020","article-title":"Rainfall effect on single-vehicle crash severities using polychotomous response models","volume":"42","author":"Jung","year":"2010","journal-title":"Accid. Anal. Prev."},{"key":"ref_24","unstructured":"El-Basyouny, K., and Kwon, D.W. (2012, January 22\u201326). Assessing Time and Weather Effects on Collision Frequency by Severity in Edmonton Using Multivariate Safety Performance Functions. Proceedings of the Transportation Research Board 91st Annual Meeting Compendium of Papers, Washington, DC, USA."},{"key":"ref_25","unstructured":"Antoniou, C., Yannis, G., and Katsohis, D. (2013, January 15\u201318). Impact of Meteorological Factors on the Number of Injury Accidents. Proceedings of the 13th World Conference on Transport Research, Rio de Janeiro, Brazil."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"225","DOI":"10.3354\/cr009225","article-title":"Weather and traffic accidents in Montreal, Canada","volume":"9","author":"Andreescu","year":"1998","journal-title":"Clim. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1016\/j.aap.2008.11.001","article-title":"Markov switching negative binomial models: An application to vehicle accident frequencies","volume":"41","author":"Malyshkina","year":"2008","journal-title":"Accid. Anal. Prev."},{"key":"ref_28","unstructured":"State Meteorological Agency of Spain and Institute of Meteorology of Portugal (2011). Iberian Climate Atlas\u2014Air Temperature and Precipitation (1971-2000), AEMET Documentation Unit."},{"key":"ref_29","unstructured":"(2018, October 30). Atlas de Portugal. Available online: http:\/\/dev.igeo.pt\/atlas\/index1.html."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1559","DOI":"10.1002\/1097-0088(20001115)20:13<1559::AID-JOC555>3.0.CO;2-5","article-title":"Circulation weather types and their influence on the precipitation regime in Portugal","volume":"20","author":"Trigo","year":"2000","journal-title":"Int. J. Clim."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2497","DOI":"10.1007\/s00382-012-1315-2","article-title":"WRF high resolution dynamical downscaling of ERA-Interim for Portugal","volume":"39","author":"Soares","year":"2012","journal-title":"Clim. Dynam."},{"key":"ref_32","unstructured":"(2018, October 30). Portuguese Institute for Sea and Atmosphere. Available online: http:\/\/www.ipma.pt\/en."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/j.aap.2004.02.004","article-title":"Poisson, Poisson-gamma and zero-inflated regression models of motor vehicle crashes: Balancing statistical fit and theory","volume":"37","author":"Lord","year":"2005","journal-title":"Accid. Anal. Prev."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1016\/j.aap.2008.10.005","article-title":"A note on modeling vehicle accident frequencies with random-parameters count models","volume":"41","author":"Anastasopoulos","year":"2009","journal-title":"Accid. Anal. Prev."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2104","DOI":"10.1016\/j.aap.2011.05.033","article-title":"A note on modeling road accident frequency: A flexible elasticity model","volume":"43","author":"Couto","year":"2011","journal-title":"Accid. Anal. Prev."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1016\/0304-4076(90)90014-K","article-title":"Regression-based tests for overdispersion in the Poisson model","volume":"46","author":"Cameron","year":"1990","journal-title":"J. Econom."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"44","DOI":"10.3141\/1635-06","article-title":"Evaluating median cross-over likelihoods with clustered accident counts: An empirical inquiry using the random effects negative binomial model","volume":"1635","author":"Shankar","year":"1998","journal-title":"Transp. Res. Rec."},{"key":"ref_38","first-page":"291","article-title":"The statistical analysis of crash-frequency data: A review and assessment of methodological alternatives","volume":"44","author":"Lord","year":"2010","journal-title":"Transp. Res. A Pol."},{"key":"ref_39","unstructured":"Greene, W.H. (2007). Limdep Version 9.0\u2014Econometric Modelling Guide, Econometric Software, Inc."},{"key":"ref_40","unstructured":"Intergovernmental Panel on Climate Change (2014). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Intergovernmental Panel on Climate Change."},{"key":"ref_41","unstructured":"European Commission (2017). Traffic Safety Basic Facts on Pedestrians 2017, European Commission Directorate General for Transport."}],"container-title":["Sustainability"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2071-1050\/11\/11\/3176\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:56:31Z","timestamp":1760187391000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2071-1050\/11\/11\/3176"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,6,6]]},"references-count":41,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2019,6]]}},"alternative-id":["su11113176"],"URL":"https:\/\/doi.org\/10.3390\/su11113176","relation":{},"ISSN":["2071-1050"],"issn-type":[{"value":"2071-1050","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,6,6]]}}}