Most of the NEWER diesel engines have an automatic shut-off to prevent excessive idling. This is better for the engine, the environment, and for those around you.
Times have changed and technology has changed. The oils are better and even with a turbo, the coking of the oil is not an issue anymore. With a synthetic oil, it was never an issue and you do not have to idle your engine to cool off the turbo. In any case, by the time you have pulled off of the interstate and come to a stop, your engine has probably idled more than it needs to to protect any internal components.
Living in the past just wastes fuel and does no good for a modern engine.