Because of the potential danger from ice accumulation, the bridge has been salted every season for decades.
Wind speeds and radial ice accumulation have a large impact on the index.
The report also said that ice accumulations on the older planes could reduce the angle at which a plane can take off without stalling.
Contracts may apply sand or salt in some locations to help melt ice accumulations.
The cause of the accident is yet to be determined, although ice accumulation on the aircraft wings is believed to have been a factor.
Freezing drizzle alone does not generally result in significant ice accumulations due to its light, low-intensity nature.
The ice accumulations grow larger as they attract liquid water from the surrounding pores.
The storm produced widespread power outages for over 2 million people due to heavy ice accumulation.
The pilot can then judge the rate of ice accumulation and make a piloting decision.
New snow and ice accumulation then replaces the ice that is lost.