Reagan Ian J, Brumbelow Matthew L, Flannagan Michael J, Sullivan John M
a Insurance Institute for Highway Safety , Arlington , Virginia.
b The University of Michigan, UMTRI , Ann Arbor , Michigan.
Traffic Inj Prev. 2017 Oct 3;18(7):716-723. doi: 10.1080/15389588.2016.1228921. Epub 2017 Apr 27.
The few observational studies of the prevalence of high beam use indicate the rate of high beam use is about 25% when vehicles are isolated from other vehicles on unlit roads. Recent studies were limited to 2-lane rural roads and used measurement methods that likely overestimated use. The current study examined factors associated with the rate of high beam use of isolated vehicles on a variety of roadways in the Ann Arbor, Michigan area.
Twenty observation sites were categorized as urban, rural, or on a rural/urban boundary and selected to estimate the effects of street lighting, road curvature, and direction of travel relative to the city on high beam use. Sites were selected in pairs so that a majority of traffic passing one site also passed through the other. Measurement of high beams relied on video data recorded for 2 nights at each site, and the video data also were used to derive a precise measure of the proximity of other traffic. Nearly 3,200 isolated vehicles (10 s or longer from other vehicles) were observed, representing 1,500-plus vehicle pairs.
Across the sample, 18% of the vehicles used high beams. Seventy-three percent of the 1,500-plus vehicle pairs used low beams at each paired site, whereas 9% used high beams at both sites. Vehicles at rural sites and sites at the boundaries of Ann Arbor were more likely to use high beams than vehicles at urban sites, but use in rural areas compared with rural/urban boundary areas did not vary significantly. Rates at all sites were much lower than expected, ranging from 0.9 to 52.9%. High beam use generally increased with greater time between subject vehicles and leading vehicles and vehicles in the opposing lane. There were mixed findings associated with street lighting, road curvature, and direction of travel relative to the city.
Maximizing visibility available to drivers from headlights includes addressing the substantial underuse of high beam headlamps. Advanced technologies such as high beam assist, which switches automatically between high and low beam headlamps depending on the presence of other traffic, can help to address this problem.
关于远光灯使用 prevalence 的少数观察性研究表明，在未照明道路上车辆与其他车辆隔离时，远光灯的使用率约为25%。近期研究仅限于双车道农村道路，且所使用的测量方法可能高估了使用率。本研究调查了密歇根州安娜堡地区各种道路上隔离车辆远光灯使用率的相关因素。
20个观察地点分为城市、农村或城乡边界，并被选中以评估街道照明、道路曲率以及相对于城市的行驶方向对远光灯使用的影响。成对选择地点，以便经过一个地点的大部分车辆也会经过另一个地点。远光灯的测量依赖于每个地点两晚记录的视频数据，该视频数据还用于精确测量其他车辆的接近程度。观察了近3200辆隔离车辆（与其他车辆间隔10秒或更长时间），代表1500多个车辆对。
在整个样本中，18%的车辆使用远光灯。在1500多个车辆对中，73%在每个成对地点使用近光灯，而9%在两个地点都使用远光灯。农村地点和安娜堡边界地点的车辆比城市地点的车辆更有可能使用远光灯，但农村地区与城乡边界地区的使用率差异不显著。所有地点的使用率都远低于预期，范围从0.9%到52.9%。远光灯的使用通常随着目标车辆与前车以及对向车道车辆之间时间间隔的增加而增加。关于街道照明、道路曲率以及相对于城市的行驶方向，研究结果不一。
使驾驶员从车灯获得的能见度最大化包括解决远光灯严重使用不足的问题。诸如远光辅助等先进技术，可根据其他车辆的存在自动在远光灯和近光灯之间切换，有助于解决这一问题。
