@classmethod
def filter_active_routes(cls, route_list, date=None):
    """
        filter an input list of route (orm) objects via is_active
        :return new list of routes filtered by date
        """
    ret_val = []
    for r in route_list:
        if r and r.is_active(date):
            ret_val.append(r)
    return ret_val
