Google travel distance vs. straight line distance

Question

I have an mid-sized(ish) app that plots a user's home address on a map, along with a number of locations. Those other locations are also displayed in a list. Each location has the distance from home displayed in the list.

Currently, distances are calculated as the shortest distance between two points (as the crow flies). I want to add a feature that will give users access to actual driving distance & time. Trouble is, calculating driving distance/time on load will max out the free quota with 100 items in the list and 25 users/day.

The only thing I've thought of so far is calculating the straight-line distance by default and adding an element to each item in the list that allows users to choose which items they want real distances/times for. I can see potential challenges when they update their address (do we keep calculating travel distance for ItemX because they requested it once?) but it would go a long way towards limiting the number of calls we make to the google api.

Has anyone else run into a similar challenge? How have you handled it?

Answer 1

This seems like not providing this quite relevant and useful information upfront would provide pretty significant friction for the user. Any treatment you provide might help to alleviate the symptoms, but will not resolve the real issue.

I'm not sure what your app does, but distances provided as the crow flies are of little practical use, unless your target audience is made up primarily of helicopter pilots...

In terms of user experience, I'm afraid the best answer is to pay for the next tier of the Google Maps API service. If you go this route, you could provide additional features to your users at a paid usage level so you can offload the additional costs.

Alternatively, if you're not ready/choose not to go that route, you could consider doling out your API calls to each user, each day to ensure that no single user puts you over the limit. Allow your users to have 100 free queries per day, and give them a heads up when they're approaching that limit.

To enable your users to query for such important data as this, you'd want to make sure this "lookup actual distance" feature is very easy to access. Perhaps a tap on the absolute distance can toggle between absolute and travel distance.

_{I'm not sure what the Terms of Service are for Google's Map API, but you might check if it's okay to cache the calls that you make so that repeat calls don't cost you.}