Final answer:
The metaphor 'we do not ride on the railroad; it rides upon us' suggests the railroad is a burden on us, rather than something we control or use freely.
Step-by-step explanation:
The best paraphrase of the metaphor "we do not ride on the railroad; it rides upon us" is option 3) The railroad is a burden on us.
This statement suggests that the railroad, which could symbolize a variety of things like technology, progress, or societal expectations, has a significant impact on our lives, potentially overwhelming or controlling us, rather than being simply a tool that we use at our leisure.
This metaphor suggests that instead of us controlling the railroad, it controls us and puts pressure on us.