TomTom made an interesting claim recently. Their summary is “when it comes to automotive-grade mapping, open source has some quite serious limitations, falling short on the levels of accuracy and reliability required for safe navigation”

This is a bold claim and they talk about recent studies that back them up. Unfortunately none of them are referenced but it’s pretty clear from the text of the article that all they are doing is comparing the accuracy of TomTom maps with existing open source maps. So they’re just generalising, this doesn’t prove a limitation with the open source process itself of course, just perhaps of a particular instance of it.

In fact having read the article I think TomTom are just misunderstanding how open source development works. Their basic complaint seems to be that open source maps are entirely community generated with no proper review of the changes made. In such a situation I’m sure the data generated is always going to be liable to contain errors, sometimes malicious, sometimes honest. But that isn’t how open source development works in general (I make no claim to know how it works for open source mapping). I’d probably call such a situation crowd-sourcing.

Successful open source projects rely on levels of management controlling the changes that are made to the central repository of the source code (or in this case mapping data). In Firefox for example every change is reviewed at least once by an expert in the area of the code affected before being allowed into the repository. Most other open source projects I know of run similarly. It’s this management that is, in my opinion, key to the success of the project. Clamp down too hard on changes and development is slow and contributors get frustrated and walk away, be too lenient and too many bugs get introduced or the project veers out of control. You can adjust the level of control based on how critical the accuracy of the contribution is. Of course this isn’t some special circumstance for open source projects, closed source projects should operate in the same fashion.

The part of their post that amuses me is when they say “we harness the local knowledge of our 60 million satnav customers, who can make corrections through TomTom Map Share“. So basically they accept outside contributions to their maps too. As far as their development goes it sounds like they function much like an open source project to me! The only claim they make is that they have better experts reviewing the changes that are submitted. This might be true but it has nothing to do with whether the project is open source or not, it’s just who you find to control the changes submitted.

There is of course one place where open source is at an arguable disadvantage. The latest bleeding edge source is always available (or at least should be). If you look at the changes as they come in, before QA processes and community testing has gone on then of course you’re going to see issues. I’m sure TomTom have development versions of their maps that are internal only and probably have their fair share of errors that are waiting to be ironed out too. Open source makes it perhaps easier to end up using these development versions so unless you know what you’re doing you should always stick to the more stable releases.

Just because a project accepts contributions from a community doesn’t mean it is doomed to fail, nor does it mean it is bound to succeed. What you have to ask yourself before using any project, open source or not, is how good are those controlling changes and how many people are likely to have reviewed and tested the end result.