In this paper comparative performance analysis of two control methods to determine Variable Speed Limit (VSL) is performed using microsimulation. A case study is performed on D100 Freeway, using both control methods, in a simulated environment of VISSIM. Calibration of VISSIM is sought using Remote Traffic Microwave Sensor data provided by Istanbul Municipality. Integration of MATLAB with VISSIM is realized via COM interface which allows implementation of user defined control methods. Results show that both control methods perform better when compared the no-control case in terms of Total Time Spent in the selected network. The feedback control strategy, based on occupancy, performs relatively better when compared to control strategy using decision tree based on threshold values of volume, occupancy and average speed. Also, the speed profiles achieved with feedback control is more homogenized when compared to resultant speed profiles from control based on volume, occupancy and average speed. It can also be concluded that application area of VSL, acceleration area, the position of signs and detectors affect the performance of VSL control systems.