Assessment of ALINEA method performance at different loop detector locations using field data and micro-simulation modeling via AIMSUN

A ramp metering (RM) or ramp signal is an effective method for traffic management, especially at merging sections in urban expressways. This research aims to assess the Asservissement Lineaire d'Entree Autoroutiere (ALINEA) method performance at different loop detector locations using field data and micro-simulation modeling via advanced interactive microscopic simulator for urban and non-urban networks (AIMSUN). The operation of RM was executed using the ALINEA method. The field data were collected from two locations in Manchester in the UK for calibration and validation in AIMSUN. Occupancy values at different loop detector locations were evaluated. The results indicated that the current simulation model could represent reality to acceptable limits. Increasing the number of detector locations at the merging entrance will decrease the occupancy value. The results showed that the effect of loop detector location is a significant factor in determining the critical occupancy of the merging section. Also, the downstream location is more appropriate for determining the congestion or critical status. The AIMSUN software showed significant consistency in representing field data of merging sections. The minimum value of GEH (Geoffrey E. Havers) that equal to 0.5 has been used to statistically and graphically demonstrate this behavior.