Switching road names from uppercase to mixed case in ArcMap?

In ArcGIS Field Calculator, you can use a simple Python expression with the string.capwords function to capitalize only the first letter of each word and change everything else to lowercase. Select Python as the Parser, and check the Show Codeblock option. Then, in Pre-Logic Script Code enter:

import string

Then in the box below that the code should be (replacing "test" with the name of your field):

string.capwords(!test!)

There are code samples for converting to Proper case in the ArcGIS help for field calculation. I can't tell if that is what you want but it is what I would expect in addresses. Proper case capitalizes all of the words, including minor/stop words such as "the." Title case does not capitalize minor words. I have seen title case functions, probably in MS Word, but not recently.

Excel 2013 does have a Proper case text function that works well. I used both Excel and ArcGIS functions when having to convert to large amounts of text to camel case (which required some final manual edits).