自民國92 年至民國96 年台北市統計發生交通事故件數總共8086 件，其中行人肇事共4081 件。交通肇事死傷人數共128 人，行人死傷人數共65 人。顯示交通肇事事故中近50%為行人肇事事故。肇事行人中以65 歲以上高齡者比例最高，主要肇事道路型態為路口。主要原因在於路口在車流特性或是道路幾何條件上，均比路段複雜也隱藏許多潛在危險性。未來高齡化趨勢，人口結構趨向高齡化，曝光在交通環境系統中的高齡者相對逐漸增加。因此探討高齡者交通安全行為也更加重要。本研究將探討行人倒數計時號誌是否能提高齡行人的風險感認，並進而影響其外顯行為。 過去肇事大多偏重統計與肇事因素分析。探討心理層面也較偏重於駕駛者，顯少探討肇事行人心理層面。然而高齡行人身心狀況較一般行人退化，動機與心理層面影響外顯行為也較一般人特殊。因此本研究嘗試以計畫行為理論為基礎，建構行人倒數計時號誌對高齡者風險感認及其外顯行為三者間的關聯架構。分析部份將以風險感認為區別變數，分別以兩種集群方法適應性類神經與兩階段分群，以判別分析決定較適用的方法。後續將風險感認集群與其他構面ANOVA分析，探討行經行人倒數計時號誌與ㄧ般號誌的高齡者風險感認的不同與行經行人倒數計時號誌的風險感認集群與其他構面差異。最後將以線性結構方程式驗證行人倒數計時號誌對高齡者風險感認與行為意向關聯模式，並以路徑分析與影響效果分析討各構面的關連程度。 研究結果顯示：（1）行人倒數計時號誌對高齡者不安全行為影響較不明顯，心理層面影響不安全行為的效果較大（2）高齡者與一般行人不同的地方為知覺行為控制構面是唯一直接影響行為意向的因子。態度必須透過知覺行為控制才能間接影響知覺行為。（3）高齡者風險感認對態度、知覺行為控制與行為意向影響均為負值。即提高高齡者風險感認，可減少不安全行為。（4）行經行人倒數計時號誌的高齡者較多偏向高度風險感認集群，行經ㄧ般號誌的高齡者較多偏向低風險感認集群。（5）行經行人倒數計時號誌高度風險感認集群的高齡者較容易產生低危險性的行為，低度風險感認的高齡者較容易產生高危險性的行為。 According to 2003 to 2007 the statistics of traffic accident, had showed that the fatality of the pedestrians are 50% out of the total fatality due to the traffic accidents. Pedestrians who are older than 65 years have a higher fatality rate than other age groups at intersection. It is complicate of traffic flow and road design and hide many danger at insection more than road The tendency of aging population and change of child birth habit decreases birthrate and ages population structure in Taiwan. There are more and more elder walk at traffic environment. This study investigates the perception of elders’ risk will influenced by the count-down pedestrian signal and the relationship with the elder’s unsafe behavior. From literature review, we find that most of studies have focused on the behavior of the drivers and the traffic accident analysis, but the studies on the pedestrian’s behavior are very few especially to the elder. The elder’s physical and mental status is rapid degenerating than people and it is special of the relationship between the elders’ mental and unsafe behavior. This study use theory of Planned Behavior to discuss the relationship between the perception of elders’ risk and unsafe behavior with count-down pedestrian signal. Describe the value of elder’perception This research finds that：（1）count-down pedestrian signal is no obvious risk, influence to unsafe behavior. But psychological have influence to unsafe behavior . （2）perceived behavior control factor is the most dominate factor in the elder’sunsafe behavior mode.It is only one facter that direct influence unsafe behavior intention factor.Attitude factor indirect influence unsafe behavior intention factor.（3）There exist a significant negative relationship between the elder’s perception risk and attitude, perceived behavior control and unsafe behavior intention factor. （4）The elder who crossed the intersection with count-down pedestrian signal are higher perception risk but the elder who crossed the intersection with traffic signal. （5）The high perception risk elder cluster who crossed the intersection with count-down pedestrian signal walk with low risk behavior and the low perception risk elder cluster who crossed the intersection with count-down pedestrian signal walk with high risk behavior.