Mathematical Problems in Engineering / 2012 / Article / Tab 1

Research Article

Traffic Congestion Evaluation and Signal Control Optimization Based on Wireless Sensor Networks: Model and Algorithms

Table 1

Nomenclature and symbols.

Location in road segment
Traffic flow speed
Vehicle trajectory
Estimated traffic data
Equilibrium speed
Traffic pressure
Sensor readings at time
Time signals exceed threshold
Temporal-spatial scales
Error from sensor k of vehicle m
Self-similar variable
Min/max green time
Cost function on lane m
Outflow in phase j
Demand flow in phase j
Saturation flow for green
Existing phase state
Observation time
Traffic density
Traffic data
Maximum traffic density
Free speed on empty road
Flow production rate
Vehicle detection threshold
Detection flag
Speed of vehicle m at sensor k
Mean square error (MSE)
Congestion factor of lane i
Effective green time
Inflow in phase j
Arrival traffic flow at stop line
Exit flow in phase j
Saturation flow for yellow
Queue length in phase i