It is clear that for both Dean and Sal, the road is a symbol for restless wandering and for new experience. Very quickly in the novel, Sal becomes hooked on travelling to the next place, and no sooner does he arrive somewhere that he wanted to get to than he already looks ahead to the next place that he plans to visit. Note the following quote that can be used to support this impression:
Now I could see Denver looming ahead of me like the Promised Land, way out there beneath the stars, across the prairie of Iowa and the plains of Nebraska, and I could see the greater vision of San Francisco beyond, like jewels in the night.
The simile comparing these cities that Sal imagines seeing in the distance to "jewels in the night" perfectly identifies the kind of anticipation and excitement that Sal feels as he thinks about travelling on and visiting these different places that, to his mind, are full of so much potential and have many different experiences waiting to happen. Critics have noted that Dean and Sal differ in their attitude to the road in that Dean measures distance by time and Sal measures distance spatially, but both characters find the allure of the road and the sense of possibility that can be achieved through perpetual travel to be compelling and addictive, at least in the early to middle stages of the novel.