Global #CompletetheMap Returns

The second Global #CompletetheMap Challenge will launch on 1 May. Nominate your location and compete with Mapillary contributors across the world—and win awesome prizes!

Edit (02-05-2018): Global #CompletetheMap Spring/Autumn Edition is now live. Follow the action on the leaderboard and take a closer look at participating locations.

In less than a week, we will be launching our second Global Challenge. Following the first, "winter" edition*, this one aims to capture the end of spring in the Northern Hemisphere and the end of autumn in the Southern Hemisphere. Last time, we had 114 participants from 42 locations, and we hope to see many more this time.

The structure of the challenge will be much the same as previous #CompletetheMap challenges, but with a few prizes awarded to the top 3 finalists. Let’s take a look at how the challenge will work, what’s on offer, and how you can participate.

How the challenge grid works

The grid will be centred around the latitude and longitude you provide us with. Every grid we create in the challenge will have 49 zones, with a total area of 49 km2. Your goal is to capture as much imagery as possible in these zones while maximising your score. As you upload images in a zone, the colour on the zone will change to reflect the percentage of total road length that now has coverage (see an example here).

If you nominate an area around water, there is a good chance part of your grid will consist of water, so keep that in mind when choosing the centre point of your area. But this might still turn out to be the optimal location. You can see in the example below that there are least two zones which do not contain any OSM ways (which the road length calculation is based on) in which images can be captured. But overall the grid is nicely centred on the downtown area.

Example #CompletetheMap challenge grid

Challenge grid around the latitude and longitude provided for Yangon

Each contributor can nominate one location, so make sure you choose wisely. If you really want to play the game, you could encourage others in your area to nominate grid locations as well. Since you get points for contributing in any grid (not just the one you nominated yourself), this will give you the opportunity to cover more around your city/town/area. Note that we might adjust the grid locations where necessary to avoid overlap and maximise the area where people can collect points.

Scoring system

In the first Global #CompletetheMap, we introduced a scoring system to balance the way different people contribute imagery. While far from perfect, the scoring system has helped encourage images useful for deriving map data.

Why do we need scoring? Take the example of someone contributing 1,000 images. This imagery could consist of 1,000 images collected over one km (one image every meter). Another person might contribute 500 images but do so over two km (one image every four metres). Which contribution is more valuable, the one with more images or the one who has covered a greater distance?

If yet another contributor comes along and captures with a 360° camera, this complicates things further. The 360° imagery gives the viewer a full panoramic perspective of the area. This would take at least four images to achieve with most smartphones. Does this make one 360° image as useful as four images from a smartphone?

The quality of the images and the capture also comes into play. 1,000 blurry images of the ground would not be useful to anyone, but currently we do not distinguish between these images and others. This is something we’ve started to think about, helping to elevate the most useful images and giving contributors feedback to make it easier to capture more useful images in the future.

We’re going to keep things relatively simple for now and continue with the scoring formula that we used in the last competition. Here’s a recap.

Score = (total UKM contributed + (images/1000)) x (1 + (count of participants/10))

  • Unique kilometres (UKM): this is the total distance of sequences contributed in areas with no previous coverage. For example, if you drove for 10 km and 7 km of it did not have existing imagery, your UKM for that drive would be 7 km.

  • Images: the total number of images the contributor has uploaded during the challenge.

  • Participants: this is the number of people participating in your grid. The idea is to encourage and reward collaboration.

All scoring will reflect contributions from the challenge start date on May 1st at 00:00 UTC to May 31st at 23:59 UTC.


There are three prizes up for grabs in the #CompletetheMap May Challenge. The top three will be determined based on their total scores at the end of the challenge.The winner of the challenge will have the option to choose any one of the three prizes. The runner-up has the choice between the two remaining items. The third place receives the remaining item.

The prizes that will be available are:

Here are a few conditions associated with the prizes.

  • To be eligible for a prize, you must reach a minimum score of 100. We reserve the right to select another entrant if the scoring has been manipulated.

  • Some countries have strict customs regulations around the import of electronic equipment. If you win one of the prizes and reside in one of these countries, we will work with you to find suitable shipping arrangements.

  • The winner will be determined as the one with the highest score 24 hours after the challenge closes (i.e. on 1st June at 23:59 UTC). This will ensure that everyone has time to upload their images before the challenge closes.

Nominate your location

If you’d like to take part in the #CompletetheMap Global Challenge, nominate your location here. You can do it any time before or during the challenge, but the earlier you nominate your location, the longer you have to contribute imagery in the area.

Remember that the grid will be centered around the latitude and longitude that you provide, so choose a location that you can easily travel around if possible. If you want to maximise your score, look for locations with a large amount of unmapped roads, paths and trails.

At the time of writing we already have 12 nominated locations. As you might notice, there is not a single negative latitude, all nominees are above the equator. It would be great to see some submissions from South America, Southern Africa, Southeast Asia, and Oceania as well.

#CompletetheMap May Challenge nominations

12 locations nominated already for the #CompletetheMap May Challenge

Following the challenge

A dedicated leaderboard has been set up for the challenge. When the challenge launches, you will be able to follow the results here. The leaderboard will contain links to the local leaderboards and grid for each location.

You can also stay up to date and share your challenge experiences using the #CompletetheMap hashtag on Twitter and Facebook.

The challenge kicks off May 1st at midnight (UTC) and will run until the very end of May at 23:59. The last one was pretty exciting, so we’re looking forward to seeing how this one unfolds now that the snow is finally melting in the north.


*Most of the Mapillary community, located on the Northern Hemisphere, faces a "winter dip" every year from about November to February, when the gloomy weather and short days don’t really support active capturing. The first Global Challenge was aiming to fight exactly that, and with this one we want to give everyone the chance to compete in more equal daylight conditions.

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