Crew compliance to shut down idling locomotives is highly variable and conditioned upon past training. In the past, crews were trained to never shut down a locomotive in temperatures below 40o F to prevent freeze damage to the locomotive engine. With a Diesel Driven Heating System, a locomotive can be shut down in freezing temperatures as well as warm temperatures. However, some crews revert back to old habits. In this case, combining the Diesel Driven Heating System with a SmartStart system takes the shutdown decision out of the hands of the locomotive operator and provides the greatest idle reduction. 2. In colder climates, select an idle reduction technology that provides the necessary heat for the locomotive engine allowing for easy restarts. The Diesel Driven Heating System allowed for easy restarts in the coldest temperatures encountered (0oF). Additional testing also showed that the Diesel Driven Heating System could maintain the engine temperature above 100oF at ambient temperatures much colder than 0oF. In warmer climates, the use of SmartStart allows for idle control by shutting down the engine when inactive. 3. Select an idle reduction technology that provides sufficient detail on engine performance such as days/hours in service, shutdown time, idle time, and reasons for idling. This allows for greater confidence in reporting actual fuel savings and emission reductions.