Call it Winter House-Keeping

At least three states have a law on the books that could be expensive for drive away drivers.
PA, MA, and CT all have a statute that requires that a commercial driver “broom off” the top and hood of the commercial vehicle he is bringing into the state, to be operated on interstate highways.
The rationale is that the sheet of snow on a box truck or semi-trailer roof could slide off and blind the motorist next to or behind the commercial truck; similarly, snow on a truck cab roof could slide down blinding the truck driver- and possibly causing a collision.
State police will distinguish between new snow which has fallen on the commercial vehicle as it travels state highways and old snow which has previously collected and may pose a danger as it may have solidified into an icy mass with destructive power. CT and MA will ticket drivers if weather is clear and the vehicle being driven is snow-covered; PA does not distinguish on the basis of weather; they cite all vehicles which are snow-covered, and from which the driver has not removed the snow cover.