Abstract: To address the issue of low traffic efficiency in the merging area of expressways, real-time information collection and interaction technology in the cooperative vehicle infrastructure environment were used. Based on the Gipps safety distance model, the METANET model was enhanced by incorporating dynamic safety distance into the variable speed limit control. The control method and model for variable speed limit control on the mainline were established and ramp vehicles were guided to merge into the mainline by use of available gaps, which improved the traffic efficiency in the merging area of expressway and the success rate of ramp merging. Finally, VISSIM and MATLAB were used to jointly build a simulation control environment to simulate and evaluate the proposed control strategy under different flow rates. The research results show that under medium and high flow rates, the proposed variable speed limit control strategy increases the speed by 8.75% and 9.28%, reduces the density by 9.45% and 9.77%, reduces the travel time by 9.29% and 8.88% and reduces the delay by 9.21% and 8.84%, respectively. It is demonstrated that the proposed variable speed limit control strategy can enhance the traffic efficiency in the merging area and improve the operational state of traffic flow.

Key words: traffic engineering; merging area; cooperative vehicle infrastructure system; variable speed limit control; safe distance; METANET model

摘要： 针对快速路合流区通行效率低的问题，利用车路协同环境下实时信息采集与交互技术，基于Gipps安全距离模型，对METANET模型进行改进；将动态安全距离融入可变限速控制中，建立起主线可变限速的控制方法和模型，引导匝道车辆利用主线可插间隙汇入，提高了快速路合流区的通行效率和匝道汇入的成功率；利用VISSIM与MATLAB联合搭建仿真控制环境，在不同流量下对所提出的控制策略进行仿真评估。研究结果表明：在中、高流量下，可变限速的控制策略使得速度分别提升了8.75%、 9.28%，密度分别降低了9.45%、 9.77%，行程时间分别降低了9.29%、 8.88%；延误分别降低了9.21%、 8.84%；证明了该可变限速控制策略能提升合流区通行效率，改善交通流运行状态。

关键词: 交通工程；合流区；车路协同；可变限速控制；安全间距；METANET模型