from the going-down dept
Recently, Techdirt wrote about the increasing number of Web sites that were dumping Google Maps and turning to OpenStreetMap (OSM) instead. But that’s only one aspect of the increasingly important digital mapping sector: another is for use with in-car satnav systems. So an obvious question is: how is OpenStreetMap doing here?
Despite the positives, recent studies have highlighted some major drawbacks of open source mapping, specifically with regard to safety, accuracy and reliability. In one particular instance, a leading open source map was compared against a professional TomTom map, and shown to have a third less residential road coverage and 16% less basic map attributes such as street names. Worse still, it blended pedestrian and car map geometry, and included ‘a high number of fields and forest trails’ classified as roads.
As TomTom explains, this is a Bad Thing:
Many drivers rely heavily on satellite navigation for precise directions, and mapping errors can be extremely dangerous, particularly in the case of one-way streets.
Just in case you didn’t get the message, TomTom concludes:
Open source mapping certainly has its benefits and can be extremely useful, particularly for pedestrians and in city or town centres. The way that the maps incorporate input from a wide community of contributors can result in impressive international coverage, whilst also driving down costs of production. However, 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.
Unfortunately, TomTom doesn’t share its sources for these figures, but Carlo Daffara pointed us to this research from December 2011 that provides a more detailed analysis of the relative merits of TomTom and OpenStreetMap in Germany. This is what it found:
With a relative completeness comparison between the OSM database and TomTom’s commercial dataset, we proved that OSM provides 27% more data within Germany with regard to the total street network and route information for pedestrians. On the contrary, OSM is still missing about 9% of data related to car navigation. According to our projection for the future, this discrepancy should disappear by the middle or end of 2012, and the OSM dataset for Germany should then feature a comparative route network for
cars as provided by TomTom.
So OpenStreetMap is actually better than TomTom for the total street network and route information for pedestrians. However, the study also considered the issue of street names raised by TomTom and “turn restrictions” — places where drivers must or must not turn:
In addition to the route network comparisons, we conducted further analyses regarding topology errors and the completeness of street name information. The results showed that the OSM dataset is not flawless; however, the trend shows that the relative and absolute number of errors is decreasing. Thus, it can also be discerned that not only is new data being added to the project database but also quality assurance is becoming a major factor within the OSM community. Our findings with regard to turn restrictions within the OSM database, which are of critical importance to navigation, showed that based on the current development rate and activity, it will take more than five years for OSM to catch up with the information found in the proprietary dataset used in our analysis.
So in Germany at least, TomTom’s criticisms about the poorer coverage of street names and “turn restrictions” are probably justified — at the moment. But what the research clearly suggests is that it is probably just a matter of time before OpenStreetMap becomes better than TomTom in this area just as it already is in terms of basic street coverage.
The fact that TomTom has chosen to highlight this current deficiency in OpenStreetMap shows two things. First, that it is watching the open source alternative very closely, and secondly, that it is sufficiently worried by what it sees to start sowing some FUD in people’s minds. But as history has shown with both open source server software and open source encyclopaedias, once vendors of proprietary systems adopt such a tactic against up-and-coming free rivals, it’s a clear sign that it’s already too late to do anything about it, and that their days of undisputed dominance are numbered.