Global #CompletetheMap III

Global #CompletetheMap is now a regular fixture on the Mapillary calendar. Our next Global CtM will launch on August 1st. Nominate your location and compete with Mapillary contributors across the world. The top 3 scores receive a GoPro Hero 5 Black for their efforts.

:exclamation::world_map: NOMINATE YOUR LOCATION HERE :world_map::exclamation:

On August 1st we will be launching our third Global Challenge. Earlier editions were held in the Northern Hemisphere’s winter and spring. Those north of 0° latitude are now in the heat of summer, while those of us below are donning our ugliest winter sweaters.

The idea of the challenge is simple. Nominate an area where you would like to contribute imagery, encourage others to help you out and see how much of that area you can complete during the challenge. The leaderboard will track results during the dates of the challenge.

Last time cameras were awarded to the top 3 participants if they surpassed a score of 100 (see below). This was a lot of fun with 5 people reaching this score and a few getting very close.

Here is ambassador Nuno on the beautiful island of Madeira with the GoPro we provided.

If you like the idea of a GoPro Hero 5 Black, take a look at how the challenge will work 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 ~50 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.

Progress in Kyiv around the area nominated by approksimator

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 August 1st at 00:00 UTC to August 31st at 23:59 UTC.


There are three prizes up for grabs in the #CompletetheMap III Challenge. The top three will be determined based on their total scores at the end of the challenge.

Each of the top 3 participants will receive a GoPro Hero 5, with equipment for the top 2 places.

  1. GoPro Hero 5 Black + Grifiti Nootle magnetic mount + Tripod adapter + 3m USB extension cable + 128gb MicroSD card

  2. GoPro Hero 5 Black + 128gb MicroSD

  3. GoPro Hero 5 Black

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 48 hours after the challenge closes (i.e. on 31st August at 23:59 UTC). This will ensure that everyone has time to upload their images before the challenge closes.

  • We’re open to suggestions if the prizes above are not useful for you. Let us know and we can find you something else that assists your image capture efforts.

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.

Some of the locations nominated 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 August 1st at midnight (UTC) and will run until the very end of August at 23:59.
Looking forward to seeing your summer and winter adventures!


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I nominated Alajuela city for the challenge, today complete the map had begun but Alajuela is not shown in the leaderboard nor have a grid. Should i wait for the city to appear in those pages before start uploading images?

@elotrojames my apologies, the grids are taking me longer than expected to generate.

Feel free to upload now though as every grid will be looking at images captured within August. Hoping to have all the grids available within the next 24 hours.

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Hello. Grid in Laos named as Kyiv, Ukrain. Please fix.

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This should be fixed now @andregrin! Thanks for pointing that out :upside_down_face:

Hello, here are my few questions.

  1. Can I or other participants I invited to join the ‘Global Complete The Map Challenge’ contribute to more than one grids far apart from each other or even from different countries?
  2. Can we join again for the next similar challenge(if any) if we can’t win this time?
  3. Do other participants I invited also need to register? Because of my carelessness, I didn’t note my longitude and latitude. How can I let you who are my team mates?

@xifan thanks for the questions.

  1. You can contribute to as many grids as you like, but of course you need to travel to those locations to collect imagery. Each participant can only nominate one location, so one advantage of having multiple participants is that you can expand the area in which you are contributing.
  2. Absolutely. We will run another Global Challenge in the last quarter of the year, probably November.
  3. Participants are automatically registered if they contribute images in the nominated zone. Did you nominate your location here? Every location submitted thus far has a lat/lon, so I’m not sure which one is your submission. Feel free to PM to clarify.

@eneerhut Hi!
I nominated Minsk city (Belarus) for the challenge. But I can’t found this location and my username in challenge table.
Could you check?


@semigradsky that’s because I haven’t created it yet :wink:
Seems like there are some new nominations over the weekend which is fantastic.

I’ll add it today so you should see it in the next few hours.


Cool! I will wait :grinning:

UPD: @eneerhut dont see yet :disappointed_relieved:

Zones in Kyiv, Ukraine, have shifted. Please return it as it was. Due to the shift, 2 days of photos were lost

The grids were regenerated to their correct size of 50km^2. I also adjusted to remove overlap which can lead to double counting of photos. Can you share a link to the images that are not being counted anymore?

Two zones in our city were raised up north. They were not superimposed before, one on another
Blue marks the old border of the zone. Red marked the present border of the neighboring zone.
In the northern region, added a lot of empty zone - Forest № 5,6,7 12,13,14,19,20,21, 27,28,41,42. There is a possibility to move them under No. 1,8 there just I photographed. The residue can be removed or added east of No. 43, 44, 45, 46

  1. You can contribute to as many grids as you like, but of course you need to travel to those locations to collect imagery. Each participant can only nominate one location, so one advantage of having multiple participants is that you can expand the area in which you are contributing.

I may be wrong, but this seems like an unfair advantage…?

if the city is big and many people want to participate ?! It will also not be fair to others, one zone will be near the house and another will have to go 15-20 km to the nearest. We have a city more than 30 km wide …

… zone not strongly influenced by, for example: Budapest 8km and 44k photo !!! a participant can easily win a prize …

Firstly, that Budapest is an example of a bad choice of grid because it is so well mapped already that it is hard to get UKM. About people needing to travel to get to location, I would expect most people would have to, because I can’t imagine people picking their house as their grid centre. About having many people participate in the grid, you have that huge multiplier advantage.

I do agree that the scoring is a bit sketchy, and the location of two grids side-by-side makes it pretty easy to get more points, too. I especially think that the score bump from having more participants is really skewed, because you could basically ask a few friends to literally take like 10 photos, and that bumps your score significantly.

I guess that grids between locations are the same size(?), but it seems a little strange that some places have 42 cells and some 36.

EDIT: Nope, they’re not even close to the same size. My town of Huntington is about 23km². North Kyiv seems to be about 40km². Barakas is about 37.

@eneerhut: What’s up with this? Why aren’t locations on even footing? I’d love to have a lot of my photos counted that weren’t in the grid, so should I nominate the next town over to get those in? EDIT: I see that it’s one per participant. Oh well. Could I at least get 50km²?

Hi Eduardo,

i submitted “Augsburg (Germany)” to the challenge about 4 or 5 days ago. Can you tell when it is set up and my City appears in the leaderboard/city list?


BTW… I am out. This competition does not feel right anymore. I just realised I got exactly 36 times 1km² zones which is obviously nowhere close to 50km² stated. I see some other grids are 7*7 zones tho I did not measure the size of each zone.

Anyways, good luck to the rest of you guys!

I’ll keep trying for now. I’m happy that my town is at least number one for now, which I think means something… and I just moved here, so I don’t have any friends to help me out. I’m not bitter, honest.

I get that the scoring is difficult to make fair with so many variables, but it really seems like for a challenge to complete the map, with grids that it seems you should fill in, the impetus is more for finding friends to help, getting more grids to fill, and uploading quantity more than covering ground. I would love to have the hardware to allow for .25 second delay like it seems some people have. It’s ironic that to get nice hardware, it helps to have nice hardware.