Well, our move from Google Maps to MapQuest is pretty much done (the start was mentioned here), so I thought I’d give a more exhaustive overview, including some more insight into our thinking.  For context, we, in this post, refers to 8z Real Estate, a real estate brokerage with a great website that drives a huge chunk of business.  (Of course, errors and opinions expressed here are all mine.)

First, if you are considering switching from Google Maps, definitely think about not leaving!  Depending on your customizations, it can be a real pain.  You can also think about it in terms of spending dollars with Google or spending dollars with your developers.

A good place to start is to make sure you know how many map views you are using.  I found three good ways to do this.

• estimate using your web analytics tools (page A uses 1 map, and is viewed X times a day, page B uses two maps and a streetview and is viewed Y times a day).  This has the benefit of being free and in your control, and not requiring you to make any code changes.  It has the detriment of being imprecise, especially if you are displaying maps via javascript that might not be tracked by your analytics tool.  I used six months of our highest traffic days to get a feel for maximum map views per day.
• ask a Google sales rep.  This has the benefit of being very precise–they can tell you how many map views they recorded for you on a given day, and, again, doesn’t require any code changes.  It has a number of downsides, though.  First, you have to get ahold of Google sales (using the ‘contact sales’ button here).  I had to submit this form at least twice before I got a call from them.  Second, you have to interact with a live person.  And third, they only have information for a single day.
• install the new Google Maps API key and look at the API console.  The upside to this is that reviewing your usage doesn’t have any external dependencies and the console  is very precise in tracking your usage.  The downside is that you are now on Google’s radar, and it may require a bit of work (depending on when you added Google Maps to your site).

We actually ended up using all three of these methods at different times, but found the API console to be the best option long term because it is the most accurate.

Once you’ve found your map view usage, check out the usage limits, which will inform your decision.  Two other considerations before you decide to move off the free Google Maps.

• If you have used the free Google geocoding service, you should re-geocode all your points, as it is outside the terms of service to display these points anywhere other than on a Google map.
• It is unclear to me when they will start the clock on the new usage limits (as announced here).  I read the new terms carefully, and you have a grace period of three months (you have to be above the free limit for three months straight) before charges start.  Note however, that once you are over for the grace period, you never can get back into it (100 days of over 25K usage followed by 3 years of under it followed by 1 day over it will still result in charges for that 1 day overage).  Additionally, Google will give a months notice of the usage limits enforcement on the Google Geo Developer blog.  That means that you’ll have at least four months of lead time.  And note that they’ve moved the enforcement deadline at least once.

Ok, you’ve decided that it simply isn’t worth the risk, and that you need to take action to avoid being charged for Google Maps lickety split.  If you haven’t, godspeed.

The options for avoiding being charged are outlined very clearly:

• Decrease your usage
• Pay for a license
• Pay for daily overages

Armed with your daily usage information (don’t forget to factor in traffic increases), you can see which of these options makes the most sense.  Contact Google enterprise sales if you feel a license purchase makes sense.  Be aware that the 25K daily limit works out to over 9M map views a year.  So if you are buying a license just to deal with daily traffic (as opposed to wanting the application to live on an intranet or some other non publicly available location, or a seasonal traffic spike), you’ll want to price out at least a 10M view license.

Once I got to talking to the Google representative, it became clear that the map license was pretty expensive.  The price range for a 30M license ranged from the mid 5 figures to the low 6 figures, per year.  We also looked at daily overages as an option.  Unfortunately this turned out to be hundreds of dollars a day.  Neither of these solutions made sense economically, so we decided to spend developer hours instead of dollars to decrease our Google Maps usage.

There are two ways to decrease Google Map usage, of course.  You can decrease use of maps all around (for example, by not having maps show up unless a user takes some action or removing extra maps), or you can migrate some or all of your current Google Maps to a different provider.

We tried both paths forward.  We removed some extra maps from the site (again, determined by our usage data), but that didn’t reduce usage enough, and also impacted users (as determined by email complaints!).

Therefore, we determined it was better to show the javascript maps every time.  We also had a technical wrinkle.  We use GWT  and are locked into Google Maps v2 (due to dependence on this library).  Google Maps v2 will no longer be supported in 2013.  I don’t believe there is a supported GWT binding for Google Maps v3, although that may get written later (here are two open source, non Google supported bindings that I found: http://code.google.com/p/gwt-google-maps-v3/ and http://code.google.com/p/gwt-maps3/ that may solve the problem for others).  Since v2 was deprecated on May 19, 2010, we knew we’d have to revisit Google Maps in the next year (by May 19, 2013, at worst), so that meant a hybrid solution (part Google Maps, part some other provider) was less appealing than otherwise.

We looked at a few different contenders to replace Google Maps.  Our criteria included:

• quick to set up
• accurate display
• free for our usage leverl
• close in features to Google Maps, at least the features we used
• looked good

In the end, I prototyped three solutions that met the first four criteria above, and asked the team for feedback on the fourth.

The solutions included:

• MapQuest javascript with the MapQuest tiles and licensed data: demo
• Leaflet javascript with cloudmade tiles and openstreetmap data: demo
• Leaflet javascript with the MapQuest tiles and openstreetmap data: demo

Some options that might be worth looking at for some, but didn’t work for us were:

• Bing Maps, which we ignored due to license limits
• Google Maps v3.  This version has significantly cheaper overages, so if you are right around the 25K usage, that might be worthwhile, but we were way over 25K mapviews, and also, as mentioned above, had GWT ties to v2.
• Rolling our own maps (ht briantimoney).  I think this wasn’t the right solution for us two reasons.  One, we were looking for something that was a relatively easy ‘drop in’ replacement for Google Maps, and crunching a bunch of map tiles didn’t seem to fit that requirement.  Two, I’m not sure there’s a lot of value in unique maps for our real estate web application (though there is in having points of interest and accurate mapping of properties).

We ended up choosing the Mapquest Javascript API for the best look and feel.

The next step was to update the pages where maps were used.  There were two main types of pages that used maps.  One type of page showed a single property on a map.  The other showed multiple markers on a map, as results of a search.

The single property page was trivial to replace.  There were a couple of interesting wrinkles.  The first was replacing the default marker icon.  I had to tweak the iconoffset and shadowoffset properties of the icon object for correct display.  Additionally, the new map had to be displayable from GWT.  This required a JSNI method run in a deferred command, in order to make sure that the MapQuest javascript has loaded.

Based on map usage data, I was hoping we could get by just replacing the single property maps, but this didn’t decrease our map usage enough.  On to search results! (If you aren’t interested in GWT, you can skip to the bottom of this post, as the next section is all about GWT gyrations.)

Replacing the search results was slightly more complex.  I reviewed all the current code and categorize our existing GWT/Google Maps based functionality into three groups.

• functionality that the MapQuest API could exactly replicate (putting a marker on a map)
• functionality that the MapQuest API had an equivalent for (displaying information on click of a marker)
• functionality that we had previously built but, in the name of simplification, weren’t going to port to the MapQuest based solution

After this categorization was done, it was fairly simple to port the needed functionality from GWT to javascript (jQuery/MapQuest).

One additional twist is formatting code shared between GWT and java (displaytag decorators, among other code).  The MapQuest javascript needed to be able to call that formatting code, as well as other GWT functionality (for example, creating a lightbox).  No sweat, right?  Here’s an example of calling GWT code from javascript.  The javascript that was calling the GWT code was running in a windows.load jQuery anonymous function.

Well, that worked fine in FF, and often in Chrome, but I was getting an error message from Chrome occasionally and IE all the time.  The Chrome error was pretty clear: ReferenceError: gwtListingUtilgetMLSIDLogoandOfficeName is not defined (gwtListingUtilgetMLSIDLogoandOfficeName is the name of one of the GWT methods that was exported for javascript to use).  The issue was that the map javascript was executing before the GWT code was fully loaded, and not finding methods it was expecting.

The solution was to chain the javascript, so that the map javascript was run via a GWT JSNI call after GWT was fully loaded, and all needed GWT functions were exported.  To provide for other GWT on load chaining, I used the onload pattern outlined here and created an addGWTOnLoadEvent.

Then I needed to create an anonymous function that GWT could call after it was loaded .  So, to recap the path of the map creation code (because it is kind of confusing to me):

• on page load, addGWTOnLoadEvent(startupSearchMap()); where startupSearchMap returns an anonymous function
• in GWT code, we export needed GWT functions to javascript: $wnd.gwtListingUtilgetMLSIDLogoandOfficeName = function(mlsId, source Id, baseImageURL, officeName, listingStatus, withBreaks) { return @com.cohomefinder.util.sharedwithgwt.ListingUtil::getMLSIDLogoandOfficeName(Ljava/lang/String;ILjava/lang/String;Ljava/lang/String;Ljava/lang/String;Z)(mlsId, sourceId, baseImageURL, officeName,listingStatus,withBreaks);};
• at the end of the export JSNI function, we call gwtonload: if ($wnd.gwtonload) { $wnd.gwtonload(); }
• which executes the anonymous function returned by startupSearchMap which then binds to the DOM element and creates the map.  Needed GWT functions are guaranteed to be present.

This would all be a lot simpler if we didn’t have valuable code written in GWT, but that is a sunk cost that I don’t ever see rewriting.

After that, it was all just testing and making a few UI tweaks.  However, the depth and maturity of the MapQuest API and community scared me a bit, with forums that weren’t as deep as the Google Maps groups I had been accustomed too, and with posts like “IE9 not supported” by the latest MapQuest API.  The API documentation was also underwhelming, with plenty of methods undocumented.  But it all worked out.  If I was doing some aggressive, bounds pushing map functionality, I don’t know if these concerns would have been more of a hindrance.

So, to recap, if you are thinking about moving off of Google Maps:

• find out your map views per day
• consider usage solutions that allow you to remain with Google Maps
• if you must move off of Google Maps, consider all other solution providers and find the one that fit
• make sure you replicate your current functionality with the map provider you choose

In general, I would rather not have moved off Google Maps (it felt like running just to keep in place, and Google Maps is a great product), but the economics dictated this choice.  I hope this post helps you decide if moving off Google Maps is right for you.