Classen Sherrilene, Shechtman Orit, Stephens Burton, Davis Ethan, Justiss Michael, Bendixen Roxanna, Belchior Patricia, Sandhu Milapt, Posse Christina, McCarthy Dennis, Mann William
College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA.
Traffic Inj Prev. 2007 Mar;8(1):69-77. doi: 10.1080/15389580600994339.
To test the effectiveness of the FHWA guidelines for intersection design.
In an experimental design we used kinematics measures from an instrumented vehicle and behavioral (error) data collected during on-road evaluations to quantify the effects of improved versus unimproved intersections (turn phase) and to determine if these intersections were safer (vehicular stability and driver confidence) for both older (65-85 years) and younger (25 -45) drivers. We analyzed kinematics data with a 2 x 2 repeated measures ANOVA and behavioral data (driving errors yes, no) with Wilcoxon sign rank test (within subject variable: intersection improved vs. unimproved) and Wilcoxon rank sum test (between subject variable: age, younger vs. older driver).
Kinematics measures (turn phase), showed three maneuvers had statistically significantly lesser side forces (measured by lateral acceleration and combined acceleration) for the improved conditions, and four maneuvers had statistically significantly greater, yet appropriate, speeds for the improved conditions. Lesser side forces indicated improved lateral stability and increased speed indicated greater confidence. Drivers made fewer errors on two of the improved intersections; but across all maneuvers, older drivers appeared to make fewer errors on the improved intersections.
This study brings empirical intersection design and safety information for engineers and city planners to consider as they plan and develop intersections. Future researchers may want to use the conceptual and analytical framework of this study to determine the effectiveness of other FHWA guidelines. Given that these intersection design guidelines benefit younger and older drivers alike, plausible policy-making opportunities are opened in the design of safe roadway systems, to benefit the broad spectrum of adult drivers.
测试美国联邦公路管理局（FHWA）交叉口设计指南的有效性。
在一项实验设计中，我们使用了来自一辆装备仪器车辆的运动学测量数据以及在道路评估期间收集的行为（错误）数据，以量化改进型与未改进型交叉口（转弯阶段）的影响，并确定这些交叉口对于老年（65 - 85岁）和年轻（25 - 45岁）驾驶员而言是否更安全（车辆稳定性和驾驶员信心）。我们使用2×2重复测量方差分析来分析运动学数据，使用威尔科克森符号秩检验（受试者内变量：交叉口改进与否）和威尔科克森秩和检验（受试者间变量：年龄，年轻驾驶员与老年驾驶员）来分析行为数据（驾驶错误，是或否）。
运动学测量（转弯阶段）显示，在改进条件下，有三种操作的侧向力（通过横向加速度和合成加速度测量）在统计学上显著较小，并且在改进条件下，有四种操作的速度在统计学上显著更高但仍属适当。较小的侧向力表明横向稳定性得到改善，而速度增加表明信心增强。驾驶员在两个改进型交叉口上犯的错误较少；但在所有操作中，老年驾驶员在改进型交叉口上似乎犯的错误更少。
本研究为工程师和城市规划者在规划和开发交叉口时提供了有关交叉口设计和安全的实证信息。未来的研究人员可能希望使用本研究的概念和分析框架来确定其他FHWA指南的有效性。鉴于这些交叉口设计指南对年轻和老年驾驶员都有益，在安全道路系统的设计中开启了合理的政策制定机会，以使广大成年驾驶员受益。
