Aubin_1,
If you are running an analysis for a location in North America, you can use the network dataset that comes with your Data and Maps DVD included in your ArcGIS installation materials. This network dataset contains speed limit information and a time-based impedance attribute you can use for drive time analysis.
If you're running an analysis for somewhere outside of North America, you will have to purchase StreetMap Premium data from Esri or create your own network dataset.
Let us know if we can provide any further assistance.