The ITS Costs Database contains three types of entries: system cost summaries, cost element ranges, and sample unit costs. 

• System cost summaries are useful to understand real-world examples of full system installations, but do not always provide an itemized breakdown of costs.
• Cost element ranges may be useful for estimating costs of specific equipment purchases since they have been compiled with many years’ worth of data using expert judgment. 
• Sample unit costs may be useful to the user who wants to review individual cost entries and construct a custom cost estimate.