Accessing Data

This Technical Concept is relevant to the following Services: xData

Characteristic

Short description

The data stored in the maps can be processed by different services and for different purposes. Therefore this data is not provided by one of the other functional services, but concentrated in an own independent service.

Use

It is often useful to retrieve raw information from the map: for instance to better understand the local behavior of the services, or to allow the implementation of advanced utilities. The determination of a time zone or map segment information for an arbitrary coordinate can be named as an examples.

Retrieving time zone information

According the Coordinated Universal Time definition, the world is partitioned into diverse areas of more or less regular stripes, for which the same local time is used:

World map of current time zones | source: wikipedia

For an arbitrary coordinate on Earth the corresponding time zone can be determined. This time zone is represented by its offset to UTC or Greenwich Mean Time (GMT). Quite often the borders of such a time zone correspond to the borders of a country or state. So the finding of the correct time zone is not trivial. Besides the time zone itself, the effective time offset is of interest, i.e. the plus or minus minutes compared to Greenwich Time. According to regional regulations, daylight saving aspects playing a role, which are defined for diverse time spans. As a result, the UTC time offset depends on location in space and time.

Technical Concept	FeatureLayer theme PTV_TimeZones
Showcase	Request the Time Zone Information
Integration Sample	Retrieving the Time Zone

Retrieving road segments data

The SegmentsRequest is an abstract operation allowing to retrieve segments according to geographical criteria. Retrieving segments information is useful to identify segments to be edited at the creation of custom Feature Layers. It is also a necessary step to identify the combined transport The combined transport is a form of transport where the vehicle in question does not drive itself but is transported by a boat or by rail (piggyback). connexions (as ferries, piggiback) that will be used as combined transport waypoints A waypoint is a geographic location used to specify start, destination and possible stopovers for a route.. Three kinds of selectors are used to specify the geographical search.

SegmentsByCoordinateRequest : select by coordinate the nearest segment(s). If the coordinates are at equal distance between several segments, all the segments are returned in the response. For example, this can be the case if the coordinates are exactly on a node of the map.	The coordinates (49.613530, 6.098357) are close to one road so only one map segment is returned.	The coordinates (49.6143206, 6.0977953) are on a node of the map so all segments connected to the node are returned.
SegmentsByIntersectingPolylineRequest : select by a polyline A polyline is a continuous line composed of one or more line segments given as a set of tuples with x,y and optional z coordinates. all the roads segments it intersects.	The polyline selector (blue) returns all map segments intersected (red).
SegmentsBySurroundingPolygonRequest : select by a polygon all road segments it surrounds. A road segment is considered surrounded if it is completely inside.	The polygon selector (blue) returns all map segments fully surrounded (red).

The SegmentResponse returns a list of MapSegment containing segmentIds, a type and other information according to the configuration of the request like the encoded geometry. It is possible to define filter criteria in SegmentsOptions by type and by network class A network class is an indicator of importance within the road segment sectioning. The road segments are divided into eight network classes by importance of the roads they represent. The network class 0 represents the most important roads, for example highways, while road segments of network class 7 are the least important roads, for example pedestrian paths. The term network level is often used synonymously, in fact the network level equals the network class plus one.. In this case, it's allow to specify for which network classes the segments shall be included in the result. If not specified, the segments will be included whatever their network class.

Good to know

Limitations

If a wrong geometry is used in a request a generic exception is sent.
If a polyline intersects or a polygon surrounds more than 5 000 segments no segments are return and a specific exception is sent.
Polygons with holes are not supported. A specific exception message will be sent.
If no segment is found, a result limitation is sent in the response.

Data Compatibility

Custom Feature Layers are map-dependent. Indeed, the segmentIds are not the same according to the map versions. When changing maps, users will have to update their custom Feature Layers. To do this, it is advisable to store the selectors used in the segmentIds retrieval step in order to have the possibility to regenerate custom Feature Layers.

Technical Concept	Custom Feature Layers