Ice Control with Brine on Highways: Implementation of Brine Spreading Technologies in County of Funen, Denmark

During the years 1996-2006, the Division of Highways and Transportation in the former county of Funen gradually replaced pre-wetted salt with brine as de-icing agent in all her ice control activities. The replacement related to 1000 kilometres of highways. Jeopardizing neither road safety nor traffic flow the spread rate of pure sodium chloride (and thus the environmental impact) in the pre-salting operations was cut back by more than one third. Compared to neighbouring counties the use of salt is less than fifty percent per square meter. In addition, supply of brine from two mixer-plants meant that six salt barns could be phased out. This made it possible to revise the staff's duty roster and thus meet the rest hour demands raised by the health and safety at work acts.

Successful pre-salting is, of course, dependent on reliable weather forecasts and on staff well trained in the art of interpreting this information. The improvements gained by the county of Funen were mainly due to the use of technologies (brine spreading with nozzles) giving a more precise spread pattern than the traditional gritting of pre-wetted salt.

Major challenges in the process have been to verify the higher quality of the nozzles spread pattern, to ensure maximum utilization of volume of brine carried by the spreading vehicles and to control the mixing of brine without getting stratification in the mixture. Moreover, of course, to ensure political approval of abandoning a well-served technology and to organize the replacement of pre-wetted salt so the process was adjusted to the ordinary plan for reinvestments in new spreading material.