Ramp Metering and the Capacity of Active Freeway Bottlenecks
Ramp Metering and the Capacity of Active Freeway Bottlenecks
复制标题
坡道计量和主动高速公路瓶颈的容量
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Levinson
中科院分区：
文献类型：
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作者：
Lei Zhang;D. Levinson
这项研究的目的是确定匝道计价器是否增加了现有高速公路瓶颈的通行能力，如果是的话，是如何增加的。在没有匝道控制和有匝道控制的情况下，对双城27个活跃瓶颈处的交通流特征进行了7周的研究。提出了一系列关于匝道控制与主动瓶颈通行能力之间关系的假设，并利用经验交通数据进行了检验。研究发现，计价器通过推迟甚至有时消除瓶颈激活(队列前过渡期的持续时间增加73%)，在队列前过渡期容纳更高的流量(2%)，以及在故障后增加排队流量(3%)来增加瓶颈容量。还检验了关于故障后流量降的双容量假设，结果有力地表明，在不同瓶颈处的流量降百分比服从正态分布(平均5.5%，标准差2.3%)。讨论了这些结果对设计有效的匝道控制策略的意义，并对未来的研究方向进行了展望。
The objective of this study is to determine whether ramp meters increase the capacity of active freeway bottlenecks, and if they do, how. The traffic flow characteristics at twenty-seven active bottlenecks in the Twin Cities have been studied for seven weeks without ramp metering and seven weeks with ramp metering. A series of hypotheses regarding the relationships between ramp metering and the capacity of active bottlenecks are developed and tested against empirical traffic data. It is found that meters increase the bottleneck capacity by postponing and sometimes eliminating bottleneck activations (a 73% increase in the duration of the pre-queue transition period), accommodating higher (2%) flows during the pre-queue transition period, and increasing queue discharge flow rates after breakdown (3%). The two-capacity hypothesis about flow drops after breakdown was also examined and results strongly suggest the percentage flow drops at various bottlenecks follow a normal distribution (mean 5.5%, standard deviation 2.3%). The implications of these findings on the design of efficient ramp control strategies are discussed, as well as future research directions.