function advtrains.is_track_and_drives_on(nodename, drives_on_p)
    local drives_on = drives_on_p
    if not drives_on then drives_on = advtrains.all_tracktypes end
    local hasentry = false
    for _,_ in pairs(drives_on) do
        hasentry=true
    end
    if not hasentry then drives_on = advtrains.all_tracktypes end

    if not minetest.registered_nodes[nodename] then
        return false
    end
    local nodedef=minetest.registered_nodes[nodename]
    for k,v in pairs(drives_on) do
        if nodedef.groups["advtrains_track_"..k] then
            return true
        end
    end
    return false
end