Ramp Metering

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Introduction ​

ALINEA ALINEA is a simple but effective ramp metering strategy that utilizes a local traffic-responsive feedback loop to maintain maximum throughput at the downstream merge area of an on-ramp. The ALINEA algorithm calculates the metering rate at each time step by computing the difference between the downstream desired occupancy and the aggregated downstream occupancy at each time step, multiplying that difference by a regulator parameter, and adding that result to the metering rate of the previous time step.

$$ r(k) = r(k-1) + {K_{R}}\times({O_{DES}}-{O_{OUT}}(k)) $$







where

Fuzzy Logic ​​





Upstream Mainline Occupancy

Upstream Mainline Flow

Upstream Mainline Speed

Downstream Mainline Speed

Downstream Mainline v/c

Ramp Demand/Queue Occupancy

Ramp Metering

Scaled Metering Rate

References ​