4

This question already has an answer here:

We have a 10,000 base of vehicle mounted moving devices which report their GPS position on a time based schedule. All that data is currently being stored in our database for several business related purposes. We think It could also provide us a base for building our own maps, but we really don't know how could this be achieved.

There must be some way to aggregate individual data points (coordinates) into line segments, thus making streets.

marked as duplicate by PolyGeo Oct 28 '16 at 6:50

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

4

Yes, it is possible but not as straightforward as the question may indicate. Points are only one of many items needed. For example, you have the points but do you have the names, start and end point of a road distinguished, z-level information (one road may cross another but not have an intersection), one-way information, and so on? If you have points then you have points that exist most likely on streets but also in driveways, parking garages, etc. What I am saying is that you have points but none of the other vast amounts of information needed to make streets. Some start points:

1) Use an already existing road product this is freely available and “adjust” the geometry of this product to your points. Even now, you really need to convert your points to centerlines so you need the number of lanes, divided highway status, and so forth.

2) You can “connect” the points and make lines based on their time-stamp in sequence but even then, you need to know the start and end of each street to break them. You can do this is QGIS using http://spatialgalaxy.net/2011/12/30/qgis-plugin-of-the-week-points-to-paths/

3) The driver of the vehicle needs to know they were going to be converted to streets so they drove consistently in one lane, did not stop at roadside stores, etc., or swing U-turns etc.

You can turn GPS points into lines easily enough using (2) but to convert them to streets or roads

  • Nice ideas, but seems your answer is missing the last part – gvasquez Dec 24 '15 at 16:42
  • See point 2. It answers the last part – If you do not know- just GIS Dec 24 '15 at 16:44
3

Your question has an active research area and many papers are dedicated to extract the geometrical properies of street network from moving objects (vehicles etc).

For example see

Apart from street names which are separate story, other information (mentioned by @If you do not know- just GIS) can be literally extracted using GPS trajectories! GPS devices report elevation along the X,Y coordinate, thus z-level information can be obtained. one-way (or two-way) information of a road segment can either be extracted as the gps points are time aware and you have a directed line segment!

I suggest to read the referred articles.

  • 1
    I agree with the Z-level although it is not so easy in practice. If you collect a point say every 30 seconds (typical for fleet transit) you are highly likely to miss the increased Z portion and additionally you have to decide how much Z increase is really an overpass. On top of this raw GPS is not accurate enough to decide this (+-15m gpsinformation.net/main/altitude.htm). One ways cannot be determined either unless you travel every street that is two way in both directions with a high level of certainty. – If you do not know- just GIS Dec 25 '15 at 0:01
  • Having the crucial information to extract two-way street is different from the possibility of inferring this knowledge from moving objects. Your quote is like saying "If we don't have GPS data for a segment we cannot construct the road segment at all". – Farid Cheraghi Dec 25 '15 at 0:24

Not the answer you're looking for? Browse other questions tagged or ask your own question.