How walkable is it?

Recently, an acquaintance asked me how to measure the walkability of a place he was visiting.  

I could have told him to just look at Walkscore (www.walkscore.com).  Walkscore assigns scores to places based on their proximity to a wide variety of destinations.  So if a place has a high walkscore AND a walkable street design (e.g. narrow streets, a grid system, etc.) it is probably pretty walkable.

But of course, some places are near lots of destinations yet have very anti-pedestrian street designs.  My old neighborhood in Jacksonville has high Walkscore ratings (at least for the neighborhood's main street, San Jose Blvd.).  Nevertheless, it is not particularly walkable because the main street in question is an eight-lane speedway. 

 So how do you find out in advance if a neighborhood is less walkable than its Walkscore rating indicates?  First, go to maps.google.com and click on the address you are interested in.   On the upper left hand corner of the map, you should see a little human-like icon, which ideally should be yellow.  Where the icon is yellow, you can drag it to the place you are interested in, see the street, and thus get a sense of how walkable the street is.   You should be able to see how wide the street is, and whether there are sidewalks. Then you can drag the icon around to neighboring streets to get a sense of how walkable those streets are.    On the other hand, where the icon is gray, this "Street View" feature is unavailable and you are out of luck.  (You can still get an aerial view of the street by clicking on the "Satellite" link at the upper right hand corner of the map; however, aerial maps don't tell you nearly as much as "Street View").  Generally, Street View is available for larger cities in the United States and a few other countries.  However, it is less available for smaller cities.