this variation is shown in various studies demand for high quality transport service such as eg express commuter buses or frequent rail transit with public transportoriented development tends to increase with income until a medium to mediumhigh income is reached moreover the demand for a high quality public transport service is potentially much greater in total than for a basic service furthermore even if as suggested in other studies changes in income affect public transport demand either directly positive impact or indirectly through increased car ownership negative impact the indirect impact may be negligible for urban public transport this is because car owners may still choose to use public transport for urban mobi lity instead of the car or use both