In Britain, a gritter is a large truck that goes out in winter and throws salt, sand, or a mix onto the road so ice is less dangerous. Weather reports say “the gritters are out,” and people know the picture: orange lights, a big box on the back, a spray of grit behind the wheels. The grit here is not pretty garden stone. It is the rough stuff that helps tyres bite and helps ice melt. The word is everyday UK English. In the United States people are more likely to say salt truck, and many of them will not know gritter at all. Taiwan does not have this machine in daily life, because icy roads are not the usual winter problem. It names the vehicle, not the driver. You would not call a brave person a gritter just because they have grit, meaning courage. That is a different use of the same little word.

撒鹽車（英國冬天用）