Guidelines for Selecting Ramp Design Speeds
| 项目名称： | Guidelines for Selecting Ramp Design Speeds |
| 摘要： | Many contextual factors should be considered in selecting an appropriate ramp design speed. Selecting a design speed for highway ramps can greatly influence project costs, right-of-way needs, and the potential project environmental and social impacts. General ramp design considerations, including ramp design speeds, are presented in Chapter 10 of the AASHTO Green Book, but the rationale of the existing guidance is in need of review. Additionally, the application of the design speed along all portions of a ramp and across the spectrum of interchange forms does not sufficiently take into account the inherent speed profiles of different ramp types. Research is needed to provide enhanced guidance on ramp design practices to facilitate the selection of more cost efficient, safer, and contextually appropriate interchange designs in all regions of the United States. The objectives of this research are to develop guidelines for selecting appropriate ramp design speeds, a summary review of the state of the practice, and recommended revisions for the AASHTO Green Book. The guidelines should facilitate the selection of an appropriate ramp design speedbased on a combination of contextual considerations and quantitative information. The guidelines should address the definition of ramp design speed, specifically the portion(s) of the ramp to which design speed should be applicable. The guidelines should also address the known safety and operational aspects of ramp design speed selection over a full range of interchange forms, ramp types, and area environments (rural vs. urban). The geometric design dimensions resulting from the suggested ramp design speeds (such as minimum radius of curvature) must also consider driver expectations and behaviors over a range of traffic conditions and the functional classification of the two interchanging roadways. Development of the guidelines may include the examination of field data and site observations supplemented with safety modeling considerations and traffic operational simulations. Speed transitions within ramps should be reviewed for performance and design policy implications. |
| 状态： | Active |
| 资金： | 400000 |
| 资助组织： | National Cooperative Highway Research Program |
| 项目负责人： | Crichton-Sumners, Camille |
| 执行机构： | MRIGlobal |
| 主要研究人员： | Torbic, Darren |
| 开始时间： | 20151110 |
| 预计完成日期： | 20190731 |
| 实际结束时间： | 0 |
相关文献
- Comparison of SHRP2 Naturalistic Driving Data to Geometric Design Speed Characteristics on Freeway Ramps
- Establish Guidelines for Designing Auxiliary Lanes on Frontage Roads
- Development of Guidelines for Ramp Metering Implementation and Performance Evaluation on I-12
- Guidelines for Activating Ramp Meters During Off-peak Hours and Weekends
- Development of Clear Recovery Area Guidelines
- Guidelines for Evaluation of Ramp Signaling Deployments in a Real-Time Operations Environment
检索历史
应用推荐
