A Survey on the State of the Art on Rational Road Geometric Design and Traffic Operations in Overseas Countries

正如海外一些已发展国家的做法一样，在道路几何设计及交通运作方面，亦须审慎考虑细节，以确保路段的合理功能与其等级类别相配合。本研究旨在收集国外有关上述问题的信息和数据，以研究日本在道路几何设计和交通运行方面的一些改进。通过访问大学和行政办公室，对一些研究人员和专家进行了访谈，并获得了相关指南、手册、研究报告和实际项目报告。在此基础上，对4个典型的信号交叉口（德国3个，英国1个）和9个环形交叉口（德国5个，美国2个，澳大利亚2个）进行了交通流录像调查。这些数据进行了分析，从用户行为的角度考虑其几何和操作功能。

As is often the case with some developed overseas countries, careful considerations should be given to details of road geometric design and traffic operations, in order to secure rational functions of road sections corresponding to their hierarchical categories. This study aims at collecting information and data regarding the issues mentioned above in some overseas countries, in order to investigate some improvements on road geometric design and traffic operation in Japan. By visiting universities and administration offices, interviews to several researchers and experts were performed, and related guidelines, manuals, research reports and practical project reports were obtained. Furthermore, traffic flow surveys through video recordings were conducted at four typical signalized intersections (3 in Germany and 1 in UK) and nine roundabouts (5 in Germany, 2 in US and 2 in Australia). These data were analyzed from a viewpoint of user behavior considering their geometric and operational features.