en Occupational and Industrial Health Occupational and Industrial Health پژوهشي Original Article <div style="text-align: justify;"><span style="line-height:1;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><b><span style="color:black">Background: </span></b><span style="color:black">Among urban features, alleys have a unique potential to influence noise patterns through their structural attributes.</span> <span style="color:black">This study aims to evaluate how specific alley characteristics, such as width, building height, and curvature, can mitigate traffic noise in urban environments, particularly in arid regions with limited greenery.</span><span dir="RTL" lang="FA"><span style="color:black"></span></span><br> <b><span style="color:black">Methods:</span></b><span style="color:black"> This field-based observational study, conducted in Isfahan, Iran, during spring 2024, investigates the noise-attenuating effects of alley characteristics, where noise levels and structural variables were analyzed using a non-linear mixed-effects model across six measurement points from 0 to 50 m within selected alleys. Initial noise levels at alley entrances averaged &asymp;70 dB (mean), decreasing to &asymp;44 dB at 50 m, demonstrating a significant reduction. </span><span dir="RTL" lang="FA"><span style="color:black"></span></span><br> <b><span style="color:black">Results:</span></b><span style="color:black"> The mixed-effects model revealed that fixed effects of structural characteristics explained 73% of the variance in noise attenuation (Marginal R&sup2; = 0.726), while the full model with random effects for alley variations accounted for 89% (Conditional R&sup2; = 0.888). Entrance width showed a positive association with noise, whereas building height and curvature significantly reduced noise propagation. Vegetation indices showed no significant impact on noise levels, likely reflecting the very low vegetation density (NDVI &asymp;0.14). This suggests that structural alley features, rather than greenery, dominate noise mitigation in arid regions. </span><span dir="RTL" lang="FA"><span style="color:black"></span></span><br> <b><span style="color:black">Conclusion:</span></b><span style="color:black"> These findings underscore the importance of urban alley design in noise management, highlighting the role of narrower entrances, taller buildings, and curved pathways to enhance livability in noise-prone urban areas. Optimizing these structural features in urban planning can significantly reduce noise exposure, and future research should explore their applicability across diverse urban contexts.</span></span></span></span></div> Traffic noise, Alley design, Mixed-effects model, Urban morphology, 67 75 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-658-3&slc_lang=en&sid=1 Zohreh Alizadeh z.alizade79@yahoo.com 100319475328460016573 0009-0007-2912-708X No Department of Environmental Science and Engineering, Isf.C., Islamic Azad University, Isfahan, Iran. Atefeh Chamani atefehchamani@iau.ac.ir 100319475328460016574 100319475328460016574 Yes Department of Environmental Science and Engineering, Isf.C., Islamic Azad University, Isfahan, Iran. Bahareh Lorestani saba12ir@yahoo.com 100319475328460016575 100319475328460016575 No Department of Environment, Ha.C., Islamic Azad University, Hamedan, Iran. Ali Asgarian asgarian.z@gmail.com 100319475328460016576 100319475328460016576 No Department of Environmental Science and Engineering, Faculty of Natural Resources, University of Jiroft, Jiroft, Iran.