Boston is made up of different kinds of sidewalk textures that a wheelchair traveler should be aware of. Some are more easily traveled on while others are not maintained and could be a nuisance and slow one down. For example, there could be a smoothed cemented walkway between cobble stones, brick that may or may not have sections that have risen up, slow-lying cobble stone tiles, or newly-laid asphalt. Sometimes there might be a crack or the sidewalk will get narrow.
We should always be aware of our surroundings and this includes debris or holes in our path. No one wants to slip and take a dive out into a crowd or street.
Here are some examples of the different sidewalk textures in Boston: