If you require to use the RadChartView control, you are right that the StepLine series is the closest series that can be used. Unfortunately, we have not implemented series that looks exactly like you require.
However, if you are willing to use another control - I suggest taking a look at our RadTmeline
control. It visualizes items with specified start date and duration. I think that it would fit your scenario.
Please feel free to ask if you need any further assistance.
Pavel R. Pavlov
Check out Telerik Analytics, the service which allows developers to discover app usage patterns, analyze user data, log exceptions, solve problems and profile application performance at run time. Watch the videos
and start improving your app based on facts, not hunches.