MapQuest Developer Blog

What you need to know about our geocoder and quality codes

Chances are you’ve heard a few things about our geocode quality codes. You’ve probably heard that they are some of the most granular in the mapping business, but you might be wondering what that means.

How can a quality code, granular or not,  help your business?

First, what is a quality code?

A quality code, simply speaking, is an indicator for the degree of accuracy in a geocode result. Many mapping applications will tell you, on a grade-letter scale, how confident they are in a geocode result. We take it a step further and analyze every piece of the query, from the street name to the zip code, so that you can ensure your drivers or deliveries know exactly where they are going.

Let’s look at an address for an example: 1060 W. Addison St., Chicago, IL 60613. This returns a quality code of L1AAA from our geocoder, which is one of the best possible geocode results, but let’s break down why.

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L1: This means that the geocoder is certain where this street address, or “Location” is located. The letters each correspond to a segment of the address. An ‘A’ is an exact match, a ‘B’ is a good match, a ‘C’ is an approximate match, and an ‘X’ indicates this information was not provided. Looking at this address, you can infer that the geocoder knows exactly where this location is, and that the street address, city and zipcode provided are exact matches. If this was a delivery address, you could dispatch your driver knowing exactly where they are going!

Assuming that, on occasion, people make mistakes when they enter an address, let’s see what happens if we tweak this address just slightly and request 1060 W. Addison Ave., Chicago, IL 60613. The geocoder now returns an L1BAA. This tells you that the geocoder is still quite certain where this location is, but that the street address wasn’t an exact match. However, a ‘B’ is still a good result, and capable of receiving a delivery.

When making a determination as to whether or not you would dispatch a driver to a location, both of these addresses are good examples. But, you may be wondering, could quality codes tell your business when you might not want to drive to an address? Absolutely! Let’s look at 2345 Martin, Dallas, TX. The geocoder returns an L1CAX. Let’s break that down:

When searching for this address, the Geocoder did find a result for 2345 Martin Luther King Jr. Blvd, so it returned an L1 because it knows where this location is, however, for the street address it returns a ‘C’ because it’s taking a best guess that the user meant Martin Luther King Jr. Blvd. The city and state gets an ‘A’ code, but the user did not provide a zip code, so the geocoder returns an ‘X.’

As a business, you might decide there is too much margin of error with this quality code, and you don’t want to waste valuable time having your driver hunt for this questionable address. Which saves both time and money, and gets you to your next delivery faster. We have more than a dozen quality code indicators, and you can read even more about them in our developer documentation.