Living in Nebraska I can vouch for a mix of gravel and salt. The gravel provides traction as the salt melts the ice. And then remains on the road, ready to be thrown up by any aggressive tread that is ahead of you. The roads department will actually figure a mixture ratio of gravel to salt given precipitation and temperature expected.
In a past life I worked for the NDOT and an auto glass company...
2011 Caprice Phantom Black 9C3
1995 9C1 Caprice
1986 Caprice Estate wagon
1996 GMC Sierra C1500
1974 SJ Grand Prix 455 well optioned with factory moon roof