Identifying Speed Hump, a Traffic Calming Device, as a Hotspot for Environmental Contamination in Traffic-Affected Urban Roads.

Despite several studies on traffic calming devices, information on particulate matter contribution by vehicle abrasion and wear nearby vertical deflections of speed humps is scant. Many studies have been performed in the recent past on heavy metal contamination at roads mainly at intersections. On the other hand, the traffic calming devices were studied for their effectiveness in reducing the vehicle speed and thereby increasing road safety, but their environmental effects are neglected. In the present study, the relation between the concentrations of Cu and Zn (marker heavy metals for traffic sources) at speed humps were nearly thrice to that in intersections, while for another marker heavy metal Pb, it was found nearly twice in comparison. Pollution load index >3 was observed upto 7.5-8.8 m distances of speed humps, and these were identified as hotspot zones for traffic-generated pollution. Furthermore, this heavy-metal-laden speed hump soil can pose a threat to living beings by virtue of resuspension produced by vehicular movements. Therefore, it is necessary to manage this emerging environmental issue, and we propose a traffic calming device with wheel cut-out provision for different vehicle classes as an alternate.