This paper describes a study of improving the waste collection process through real-time simulation-optimizationbased onultrasonic level measurements. In the study,ultrasonic level meters are placed inside waste containers and programmed to send measurement values to a computer server via GPRS at regular intervals. The measurement values are processed in a simulation-optimizationprogram in order to determine which waste containers to visit a specific day. The program tries to minimize the number of collections over time while at the same time find the best routesto take. The aim of this approach is to minimize the driving distance and thereby minimize CO2 emissions.