Ramp Metering

​

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 𝒓(𝒌):ramp−metering rate at time index 𝑘 𝑲_𝑹:constant regulator 𝑶 ̂:desired downstream occupancy 𝑶_𝒐𝒖𝒕 (𝒌):aggregated downstream occupancy at time index 𝑘 𝑳𝑳:low limit metering rate 𝑯𝑳:high limit metering rate

Fuzzy Logic ​​

References ​