var ds = new DataSourceRequest()
{
	Filters = [new FilterDescriptor("FieldName", FilterOperator.IsEqualTo, "Route #")],
	Sorts = []
};
{

Console.WriteLine(ds.ToODataString());

$count=true&$filter=(FieldName%20eq%20%27Route%20#%27)&$skip=0

This results in a malformed url as the last part of of the query is interpreted as a fragment due to this character not being encoded.