 As society ages, a large amount of human factors related research has been carried out into the subject of the safety of the elderly in their daily lives. However, most research focuses on the general elderly population and there is a serious lack of research into elderly sufferers of Parkinsons disease PD, who receive a substantial amount of attention in medical circles. In the investigators previous study, the investigators have found that patient with PD had decreased ability to cross the road as compared to agegender matched control subjects. Hence, this research proposed several training programs to enhance the safety of crossing road, including safe place finding,roadside search,time gap and perception of others intentions. The investigators will compare the parameters of crossing road ability before and after training programs in patients with PD and control subjects. 