[Fulltiming]

Fluffy snow good, a flat glaze of ice not good. Icing typically occurs when the temperatures have risen enough that the snow has melted then refrozen forming ice. If the roads have been sanded or salted and it hasn't rained on top of it, you should be OK if you drive slowly. Heavily traveled roads are more likely to be free of ice (other than bridges and elevated sections) than less well traveled roads. At night the slush will refreeze and become ice. Sunshine and lots of traffic to keep the streets heated up are your friends.

The cables are likely air tank drain releases. Probably one in the back (wet tank) and two in the front (front and rear brake air tanks).