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Abstract. Fog, freezing rain, and snow (melt) quickly condense on road surfaces, forming black ice that is difficult to identify and causes major accidents on highways. As a countermeasure to prevent icing car accidents, it is necessary to predict the amount and location of black ice. This study advanced previous models through machine learning and multi-sensor-verified results. Using spatial (hill shade, river system, bridge, and highway) and meteorological (air temperature, cloudiness, vapour pressure, wind speed, precipitation, snow cover, specific heat, latent heat, and solar radiation energy) data from the study area (Suncheon–Wanju Highway in Gurye-gun, Jeollanam-do, South Korea), the amount and location of black ice were modelled based on system dynamics to predict black ice and then simulated with a geographic information system in units of square metres. The intermediate factors calculated as input factors were road temperature and road moisture, modelled using a deep neural network (DNN) and numerical methods. Considering the results of the DNN, the root mean square error was improved by 148.6 % and reliability by 11.43 % compared to a previous study (linear regression). Based on the model results, multiple sensors were buried at four selected points in the study area. The model was compared with sensor data and verified with the upper-tailed test (with a significance level of 0.05) and fast Fourier transform (freezing does not occur when frequency = 0.00001 Hz). Results of the verified simulation can provide valuable data for government agencies like road traffic authorities to prevent traffic accidents caused by black ice.

Amid the accelerating rise in temperature worldwide, the number of summer heat patients continues to increase despite the nation's No. 1 rank in terms of ratio of heat shelters per area in Seoul. This study analyzed the effect of shuttle operations using the System Dynamics-GIS model to secure the mobility of cooling shelters for the vulnerable population in Seoul. To input into the System Dynamics model, spatial information consisting of the vulnerable population for each Dong in Seoul, cooling shelter (capacity, location), and DEM data were analyzed in GIS. By designing a stock-flow model based on the spatial input information, the pattern of decrease of the heat wave exposure rate according to the evacuation rate of the vulnerable was analyzed in time series. The scenarios consisted of not operating a shuttle bus (Scenario 0), operating a shuttle bus (Scenario 1), and efficient shuttle distribution with the operation (Scenario 2). The heat wave exposure rates of each scenario were 83.5%, 74%, and 59.58%. The heat wave exposure rate of the vulnerable group due to shuttle operations has decreased by as much as 23.92%, and this study’s results can serve as primary data when establishing policies related to shuttle operations.

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