Is a propane "ice melt" torch effective for melting ice on a driveway?

No. But..I HAVE hooked up the garden hose to the hot water outlet in the garage that my washing machine hooks up to, and have hosed down icy areas with hot water to melt the ice. ;-)

That will work if you can move out the water before it freezes, and your cost in propane will far exceed any benefit from a clear driveway. Try a non-toxic ice melt, which is good for the plants.

I’ve run a blowdryer out to the car with extension cords to thaw out frozen locks and door seals.