This plugin implements the ALINEA ramp metering algorithm in PARAMICS. The ALINEA algorithm, proposed by Papageorgiou et al, is a local feedback ramp metering strategy, which attempts to maximize mainline throughput by maintaining a desired occupancy on the downstream mainline freeway. Compared to other traffic-responsive ramp metering algorithms, ALINEA is remarkably simple, highly efficient, and easily implemented. According to the results from field tests and simulation-based studies, ALINEA has very good performance.
The original ALINEA algorithm requires occupancy data from a detector located downstream of the onramp. However, most mainline detectors in the field are actually located upstream of the ramp. Moreover, there were some quests to use flow data instead of occupancy data. The ALINEA algorithm implemented in the plugin is thus modified to meet these needs.