Here is a pretty straight-forward approach using only the free tools available in the ET GeoWizards toolset for Arc:
- Open the ET GeoWizards toolbox. In the 'Point' menu, select 'Create Station Points'
- It will prompt you to enter your polyline layer and an output file, and on the subsequent screen, ask for your distance between stations (it will indicate the unit of measure based on your data coordinate system). Select 'Finish' and the tool will output a set of points along all lines (based on line direction) at the prescribed distance.
- Open the ET GeoWizards toolbox again and in the 'Polyline' menu select 'Split Polyline with Layer' - this will appear locked, but the free functionality will work for your purposes.
- Enter your original polyline layer as the input 'layer to split', and your newly created point file as the 'split layer'.
Your output from this operation will be all of your original polylines, split into segments of your desired length (with remainders segments left over where lines are not evenly divisible). Note that this approach will create points at the start of each polyline segment that is shorter than 2 miles, but this should not be an issue as the subsequent 'split' operation will have no affect on these shorter segments. If this is problematic, you could simply select only lines whose length exceeds 2 miles for the operation.