It was an overland route where merchants carried goods for trade. But it was really two routes, one that connected the eastern Mediterranean to Central Asia and one that went from Central Asia to China. Further complicating things, the Silk Road involved sea routes. Many goods reached Rome via the Mediterranean, and goods from Central Asia found their way across the Pacific to Japan and even Java. So we shouldn't think of the Silk Road as a road, but rather as a network of trade routes. But just as now, the goods traveled more than the people who traded them. Very few traders traversed the entire Silk Road.