| 摘要: | 背景:
自行車缺乏醒目性因此不容易被汽車駕駛者察覺。在夜間視線差，不少自行車於夜間行駛時，沒有裝置尾燈也沒有頭燈，因此較容易發生意外事故；由於汽車駕駛者較難發現到自行車騎士，一旦發生事故時駕駛者減速反應時間較短，而可能導致嚴重程度的機率也較大。許多研究提出在夜間「醒目度」的重要性，以自行車來說「尾燈」是夜間設備中最明亮也是最醒目的標誌，因此尾燈的使用可以降低夜間事故的發生率以及降低傷亡的嚴重度。
目的:
本研究探討在夜間觀測車輛超越自行車時，是否會因尾燈醒目程度不同，而有不同的超車距離。
方法：
從2014年06月至11月的觀測性研究，在台北市信義區吳興街包含有自行車道和沒有自行車道的道路收集共1072輛汽車。測量變項為車輛的車距、自行車尾燈型態(放射狀小人燈/固定燈/閃爍燈/沒有尾燈)、車輛的型態(轎車/休旅車/小巴/貨車/其它)、(非)計程車及對向車道30公尺內有無來車。以描述性統計、卡方檢定(chi-squared test)分析不同型態尾燈對於車距的影響;將車距劃分成大於1.5公尺(安全距離)和小(等)於1.5公尺(危險距離)後，用二元邏輯斯迴歸(Binary LogisticRegression)分析上述測量變項對車距的影響。
結果:
在有自行車道，尾燈為放射狀小人燈駕駛者給予的車距最長為1.83公尺±0.32；在沒有自行車道，則是沒有尾燈為1.92公尺±0.49。二元邏輯斯迴歸Omnibus檢定所選取的變數對整體模型具統計顯著 (p< .05)，Hosmer-Lemeshow檢定邏輯斯迴歸模型預測車距1.5公尺有良好的配適度(p> .05)。當車輛超越自行車時，車距大於1.5公尺的機率以各變項依序來說，和非轎車相比轎車機率會減少32%；和非放射狀小人燈相比放射狀小人燈機率會增加133%；和有尾燈相比沒有尾燈機率會增加75%；和沒有自行車道相比有自行車道機率會減少28%；和對向車道30公尺內沒有來車相比對向車道30公尺內有來車機率會減少56%。
結論:
不同型態的自行車尾燈，會影響駕駛者超越自行車者時的車距。若以車距1.5公尺當作分界，結果發現不管在有無自行車道當汽車駕駛者超越自行車時，車距大於1.5公尺的尾燈以放射狀小人燈佔的比例最多。
本研究有兩點額外結果發現，第一點，「沒有尾燈」時，駕駛者給予有尾燈較多的車距，可能是因為當駕駛者發現自行車沒有尾燈時，視騎士為「危險駕駛!」因而給予較多車距；第二點，發現對比度(contrast)和醒目度(conspicuity)兩者的關係，當我們在考量目標物醒目程度時，須注意到目標物與環境兩者間的對比狀態。
Background：
Due to lack of conspicuity, it is hard for car driver to pay attention to bicycle driver especially at night. This problem could increase the incidence rate of crash accident and even increase the severity of the accident. Many researches showed the importance of the conspicuity. For bicycle, the brightest and the most conspicuous night equipment is taillight. Therefore, the use of taillight could decrease the incidence rate and the severity of casualties at night.
Object：
Tail-light is the brightest and notable target on night-transport equipment. We observe the difference in distances between car and bike resulted from four different tail-lights when car-driver overtaking a bicycle.
Methods：
This is a Observational Study and we collected cases in Wu-xing street, Xing-yi district, Taipei during June 2014 till November 2014. Total 1072 cases were enrolled, and we exam the relationship of the distance between car and bike and each variables. The variables includes: the four different types of tail-light, types of cars (sedan, SUV, mini-bus, van, ect. ), taxi or non-taxi, whether if there is car in the opposite lane.
Results：
In road with cycle lane, the longest overtaking distance is 1.83±0.32 meters while car overtaking bicycle. In road without cycle lane, the longestovertaking distance is 1.92±0.49 meters. While car overtaking bicycle, the compare of different variables in the chance of overtaking distance more than 1.5 meters : cars decrease 32% than other vehicles; laser projection taillight increase 133% than non-laser projection taillight; taillight decrease 75% than with without taillight; with cycle lane decrease 28% than without cycle lane; with opposite traffic within 30 meters decrease 56% than without opposite traffic.
Conclusions：
Different types of taillight would affect the overtaking distance while car driver overtaking a bicycle. This study reveal two additional results : one is that “When taillight type is no-taillight, car drivers tend to have more overtaking distance. ” This may due to car drivers consider the bicycle rider without taillight as dangerous rider. The other one is “When we considered the conspicuity of an object, we have to pay attention to the contast of the object and the environment.” |
