Answer: The road, crucifix/cross, sidewalks, railroads, and so much more.
Step-by-step explanation: Roads are parallel so that everyone can get to the same place in different lanes. This is important because lines that aren't parallel will inevitably meet, meaning that a highway would eventually merge its two lanes. This happens, but most of the highway is parallel. The same is true of sidewalks and railroads. The crucifix/cross is a Christian symbol, and while I'm not Christian, I'm sure it's important to a lot of people who are.