Every day, trucks carrying hazardous materials (hazmat) in a large and densely populated city expose public health risks to the residents of the city as well as risks to the economic assets in the area. In this paper, we introduce a new risk model that considers population exposure along a route and the duration of such exposure, the latter being variable due to the congested nature of road transportation in urban areas. We have developed a spatial decision support system (SDSS) for quantitative risk analysis and the calculation of minimum-risk paths as well as their visualization on digital maps. We illustrate the usage of our proposed model and SDSS via a case study using the real road network of Istanbul, Turkey, a large metropolitan area with more than 15 million residents. We analyze Istanbul's hazmat transportation risk profile using risk analysis techniques via our interactive Geographical Information Systems (GIS)-based decision support system. We then produce a risk map of the city and run several routing scenarios between selected hazmat shipment origins and destinations. Results suggest that the hazmat routes under the new model may not always match with how hazmat is usually transported, with an economic decision-making perspective, in an urban area. Our proposed approach provides decision makers with new insights into urban hazmat transportation and is likely to reduce the consequences of incidents with large impact on public health.

每天，在人口稠密的大城市中，运送有害物质（危险品）的卡车都会给城市居民带来公共卫生风险，也给该地区的经济资产带来风险。在本文中，我们引入了一种新的风险模型，该模型考虑了沿途人口的暴露程度以及暴露的持续时间，由于城市道路交通的拥堵性，后者具有可变性。我们已经开发了空间决策支持系统（SDSS），用于定量风险分析和最小风险路径的计算以及它们在数字地图上的可视化。我们通过使用土耳其伊斯坦布尔的真实道路网络的案例研究，说明了我们提出的模型和SDSS的用法，土耳其伊斯坦布尔是一个拥有1500万居民的大都市区。我们分析伊斯坦布尔 通过基于交互式地理信息系统（GIS）的决策支持系统使用风险分析技术来评估危险品运输的风险状况。然后，我们生成城市的风险图，并在选定的危险品运输起点和目的地之间运行几种路线选择方案。结果表明，从经济决策角度出发，新模型下的危险品路线可能并不总是与通常如何运输危险品相匹配。我们提出的方法为决策者提供了有关城市危险品运输的新见解，并有可能减少对公共卫生产生重大影响的事故后果。然后，我们生成城市的风险图，并在选定的危险品运输起点和目的地之间运行几种路线选择方案。结果表明，从经济决策角度出发，新模型下的危险品路线可能并不总是与通常如何运输危险品相匹配。我们提出的方法为决策者提供了有关城市危险品运输的新见解，并有可能减少对公共卫生产生重大影响的事故后果。然后，我们生成城市的风险图，并在选定的危险品运输起点和目的地之间运行几种路线选择方案。结果表明，从经济决策角度出发，新模型下的危险品路线可能并不总是与通常如何运输危险品相匹配。我们提出的方法为决策者提供了关于城市危险品运输的新见解，并有可能减少对公共卫生产生重大影响的事故后果。