A road surface freezing model using heat, water and salt balance and its validation by field experiments

- The flux of water dispersion due to passing vehicles was formulated.
- We developed a new road freeze prediction model in consideration of deicer.
- The validity of the model was indicated through comparison with field tests.
- The salt dissolution rate on the icy road was examined by sensitivity analysis.

This study aims at helping optimize the application of deicing agents on the winter road surface. In this regard, field tests were conducted for observing how water and deicing agents (= salt) disperse due to passing vehicles as well as for calculating the dissolution rates of salt on the road surface. Additionally, we developed a one-dimensional time-dependent model for the prediction of freezing on a road surface. It takes into account the effects of salting and passing vehicles and is called the RSF-SV model. Its validity was examined by using field test results.Based on the test results, the relationship between the amount of water dispersed due to passing vehicles and the thickness of the water film on the surface was formulated, and the dissolution rate of salt on the icy road surface was identified. The RSF-SV model used these results for successfully reproducing the time-series changes in the surface temperature, the ice film thickness, the water film thickness, the salt concentration, and the amount of residual salt on the ice-covered road surface after the application of deicing agents.