  Over 30 million tons of deicing salt is applied on U.S. roads annually at a
cost of roughly $1.2 billion and with significant negative environmental
impact. Therefore, it is desirable to reduce salt use while maintaining winter
road safety. Automatic adjustment of application rate in response to road,
weather, traffic, and other conditions has the potential to achieve this goal.
  In the US, salt application rates are typically pre-set manually based on
roadway classification, cycle time, desired level of service (LOS), and
expected traffic, road, and weather conditions. The operators can temporarily
change the application rate manually based on their experience and
observations. Current spreader automation mostly involves adjusting discharge
rate in response to spreader speed, although pavement temperature sensors are
likely to be adopted in the future.
  This paper explores extending spreader automation for adjusting salt
discharge rate on curves, inclines, and other areas with historically high
accident concentrations. First, we propose the use of gyroscopic sensors and
inclinometers on board the spreader to adjust discharge rate in real time in
response to curves and inclines. The second part of the proposed solution
includes the installation of roadside Radio-Frequency Identification (RFID)
tags that can communicate the length and the severity of the hazard zone to an
RFID reader on board the spreader to automatically adjust discharge rate
accordingly.
  Our proposed methods have the potential to reduce salt use and operator
fatigue, while increasing winter road safety without adding excessive cost or
complexity to the existing spreader systems in the US.
