A Semiquantitative Approach to Assess Uncertainty for Predicting Road Surface Temperature if a Sensor Fails at a Station

Abstract

Road surface temperature (RST) plays an essential role in analyzing road surface conditions during winter in countries with adverse winter climates. A reduction in RST can have a negative impact on road safety due to decreasing vehicle grip on the road surface. Therefore, decision makers need to monitor low surface temperatures and plan for winter road maintenance. However, RST sensors can fail for different reasons, such as power outages. RST sensor failure will lead to lack of information about the road surface, which can be problematic, especially for critical road segments. Hence, the novelty of this study is to use a deep learning algorithm to predict RSTs in road segments if a sensor fails at a station using historical data from two other road stations. The mean absolute error in the proposed model is 0.453 and the model explains 98.6% of observations. In addition, since the adjustment of deep learning parameters (e.g., hidden layers, optimizer, activation function, etc.) is associated with epistemic uncertainty, a semiquantitative approach is developed for uncertainty assessment. With this approach, the most important and uncertain parameters in RST prediction models can be identified. The results have shown that the optimizer is the most uncertain and important parameter.