Where I live I have to ride my bike to my University every day and I always use the sidewalk to get there. Before I moved to go to university I always stuck to the roads and bike lanes, but where I live now the drivers are atrocious! There are at least two crashes every day on the street that I live on, because of this I now ride strictly on the sidewalk so that I don't become an unfortunate statistic. I feel like if you would be in danger otherwise, it is completely okay to ride on the sidewalk.