Urban Development Policy Making

Urban Development Policy Making

Comparative Evaluation of Traffic Calming Measures Effectiveness in Reducing Vehicle Speeds (A Field Study in Tehran)

Document Type : Original Article

Authors
1 Assistant Professor of Civil Engineering, North Tehran Branch, Islamic Azad University, Tehran, Iran
2 Master of Science in Road Engineering, Tarbiat Modares University, Tehran, Iran
10.22034/judpm.2026.577927.1094
Abstract
Traffic calming measures are widely used in urban streets to reduce vehicle speeds and improve road safety. This study evaluates the effectiveness of several traffic calming measures implemented in Tehran, including plastic speed humps, sinusoidal speed humps, median islands, pavement treatments, and rumble strips. Vehicle speeds were collected under free-flow traffic conditions using laser speed measurement devices. A before–after analysis framework was adopted, and independent sample t-tests were used to compare vehicle speeds before and at the location of each traffic calming measure. The results indicate that plastic speed humps, plastic speed humps combined with median islands, and sinusoidal speed humps produced the greatest reductions in vehicle speed. In contrast, rumble strips did not show statistically significant effects on speed reduction. The findings also demonstrate that speed reduction generally begins before the installation point and gradually recovers after passing the calming device. Overall, the study confirms that properly designed traffic calming measures can effectively reduce operating speeds and improve urban traffic safety. Combined calming strategies were found to be more effective than isolated measures. The results can support evidence-based decision-making for selecting suitable traffic calming measures in urban streets.
Keywords
Subjects

1.    Nilsson G, Traffic safety dimensions and the power model to describe the effect of speed on safety, Bulletin 221, Lund Institute of Technology, Lund, 2004. Available from: https://lup.lub.lu.se/search/files/4394446/1693353.pdf
2.    Elvik R, Speed and road safety; new models, TOI report 2014/1296, Institute of Transport Economics TOI, Oslo, 2014. Available from: https://www.toi.no/getfile.php/1335303-1394518314/Publikasjoner/T%C3%98I%20rapporter/2014/1296-2014/1296-2014-Sum.pdf
3.    Rahimy A, Abbasy V, Evaluating the effect of speed reduction devices on reducing traffic accidents”, The 7th National Congress of Civil Engineering, Zahdedan, Iran, 2014 (In Persian).
4.    Wahed, T, Hashim, I, “Effect of speed hump characteristics on pavement condition”, Journal of traffic and transportation engineering Volume 4, Issue 1, February 2017, Pages 103-110, 2017. Available from: https://www.sciencedirect.com/science/article/pii/S2095756416300216
5.    Gitelman W, Carmel R, Pesahov F, Chen S, Changes in road-user behaviors following the installation of raised pedestrian crosswalks combined with preceding speed humps on urban arterials, Transportation Research Part F: Psychology and Behaviour, Volume 46, pp. 356-372, 2016. Available from: https://ui.adsabs.harvard.edu/abs/2017TRPF...46..356G/abstract
6.    Moreno A, García, A, Use of speed profile as surrogate measure: Effect of traffic calming devices on crosstown road safety performance, Accident Analysis & Prevention, 61, pp.23-32, 2011. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0001457512003697
7.    Hassani Nasab Sh, Sharify Rad A, Zahedy M, The effect of calming measures on the speed of traffic flow with use From statistical methods, Transportation Research Journal, Vol 56, 2020.
8.    Rizzi M, Khabat A, Johan S, Fredriksson R, Kullgren, A, The safety effect of increased pedestrian protection, autonomous emergency braking for pedestrians and bicyclists on passenger cars, and speed management, Traffic Safety Research, 6, e000046. Available from: https://doi.org/10.55329/hbtq4489.
9.    Batomen B, Cloutier M, Carabali, M, Hagel B, Howard A, Rothman L, Perreault S, Brown P, Ruggiero E, Bondy S, Traffic-Calming Measures and Road Traffic Collisions and Injuries: A Spatiotemporal Analysis, Am J Epidemiol. 2024 May 7;193(5):707-717, Available from: doi: 10.1093/aje/kwad136, 2024.
10.              Ambros J, Tomešová L, Jurewicz C, Valentová V. A review of the best practice in traffic calming evaluation. Accid Anal Prev. 2023 Sep; 189:107073. Available from: doi: 10.1016/j.aap.2023.107073. Epub 2023 May 29. PMID: 37257356.
11.              Shwaly S, Osman R, El-Ayaat A, Assessing Multifaceted Effects of Speed Humps and Bumps: Travel Time, Safety, and Environmental Considerations, Civil Engineering Journal, Available from: https://doi.org/10.28991/CEJ-2024-010-07-07
12.              FHWA Office of safety Web site, "Focused Approach to safety- purpose of the Focused Approach". Available from: http://safety.fhwa.dot.gov/fas
13.              The Effects of Traffic Calming Measures on Pedestrian and Motorist Behavior, Publication Number: FHWA-RD-00-104, Date: August 2001. Available from: https://pdhonline.com/courses/c269/FHWA_RD_00_104.pdf
14.              Traffic Calming: State of the Practice. U.S. Federal Highway Administration (FHWA) report, Last Updated (Year): 2016. Available from: https://books.google.com/books/about/Traffic_Calming. html?id=oH0sAQAAMAAJ
15.              Damsere-Derry J, Ebel B, Mock C, Afukaar F, Donkor P, Kalowole T, Evaluation of the effectiveness of traffic calming measures on vehicle speeds and pedestrian injury severity in Ghana, Traffic Inj Prev. 2019; 20(3): 336–342. Available from: doi:10.1080/15389588.2019.1581925.
16.              Alahwal A, Elkousy O, The Production of Traffic Calming and Permeability in Historic Cairo’s Open Spaces, Public Space in Cairo and Khartoum., Special Feature, 2024. Available from: https://journals.openedition.org/esma/698?lang=en
17.              Alshabibi N, An Impact Assessment of Speed Humps’ Geometric Characteristics and Spacing on Vehicle Speed: An Overview, infrustructures, 2025, 10, 190. Available from: https://doi.org/10.3390/infrastructures10070190.
Volume 3, Issue 2
Summer 2026
Pages 283-298

  • Receive Date 23 October 2025
  • Revise Date 22 December 2025
  • Accept Date 20 February 2026
  • Publish Date 02 July 2026