城市快速路功能可靠度量化评价与实证研究

Quantitative Evaluation and Empirical Study on Urban Expressway Functional Reliability

依据《城市道路工程设计规范》关于快速路功能的阐述,提出了城市快速路功能可靠度的概念,作为定量评价快速路功能实现程度的概率测度指标。结合行车速度和车头时距变异系数,构建了快速路功能可靠度的计算方法,并探讨了其与服务水平指标相比,对于评价道路实际使用功能与规划设计功能之间吻合程度方面的异同点。最后以郑州市3处快速路路段为例,基于视频采集实地数据资料,论证了行车速度和车头时距变异系数之间的独立性。结果表明:功能可靠度的计算结果与服务水平分析结果相吻合,并可对服务水平分析结果进行补充,验证了所提方法的可行性与适用性;与服务水平比较,功能可靠度量化了道路功能的完成程度,且无需给出明确的分界点,更有助于管理者做出判断与决策。

According to the function description of urban expressways in Code for Design of Urban Road Engineering, we put forward the concept of urban expressway functional reliability as the probability measure index for quantitatively evaluating expressway function realizing degree. Combining with vehicle speed and headway variation coefficient, the calculation method of expressway functional reliability is constructed. Furthermore, comparing the functional reliability with the service level index, their similarities and differences in evaluating the coincide degree between road service function and designed function are discussed. Finally, taking 3 expressway sections in Zhengzhou City for example, based on the video collected real data, the independence between vehicle speed and headway variation coefficient is proved. The result shows that （1） the calculation result of functional reliability agrees well with the result from service level analysis, and could provide additional information for the service level analysis result, which furthermore testified the feasibility and applicability of the proposed method ; （2） compared with service level, functional reliability quantified the realizing extent of road function, and the specified boundary value is not needed, it is more helpful for management Judgment and decision-making.