That's silly. One voter might drive a 2014 BMW and live one mile from the polling station. Another might live in a rural area with no car or bus service. Which person has to work harder to vote? The facts of life are that some people have to work harder than others to enjoy the conditional rights of life, liberty, and the pursuit of happiness. Voting isn't any different.
This example is silly. First of all, there's not one polling station.
There are several. Why are there several? To make it as easy as possible to give the most people access. To limit the amount of work people have to do to vote. It would be impossible to have a polling station the same distance from everyone's home. It is not impossible to hold an election without attempting to disenfranchise voters along economic lines.
As for your comparison between voting access and the hard knock lives of lower income children, does your volunteer work entail intentionally making their lives more difficult? If there was a way to even the playing field so that the kids you work with were able to get the same results from the same amount of work, wouldn't that be the better option? That's not something possible to enforce insitutionally. But it is possible to create as level a playing field as possible for a basic right.