some of you need to work with SPEED LIMITS in a way the PTV engines do not handle them by themselves (e.g. xServer2 does not return speed limits, at least in version x2.24 (august 2021)). We therefore offer the opportunity to deal with specific side tables and I'd like to give you some details about how these tables work.
- We provide speed limits based on pairs of files per IU (=integration unit, usually a country):
- *.spl : this file contains the structure definition of set of "limit scenarios". Usually somewhere between 10 and 50 scenarios within a single IU
- *.l2s : this file contains a very detailed list of all the segments in the IU plus a reference to the scenario ID that applies to such a segment.
- These pairs are provided per IU
- As segment IDs are not stable between map versions the side tables have to be updated whenever you update the underlying map.
- SPL: Here are the columns of the SPL file:
Field Name Datatype Attribute type Min Max Default Description 1 ID NUMBER 10.0 PK 1 2147483647 1 unique key of speed limit 2 LEGALLIMITTYPE NUMBER 10.0 Man 0 3 0 implicit or explicit speed limit 3 LIMITTYPE NUMBER 10.0 Man 1 8 1 kind of speed limit 4 LIMITWEATHERCONDITION NUMBER 10.0 Man 0 7 0 weather related conditions 5 LIMITDRIVERCONDITION NUMBER 10.0 Man 0 7 0 driver related conditions 6 LIMITTIMECONDITION NUMBER 10.0 Man 0 3 0 time related conditions 7 TIMEPERIODID NUMBER 10.0 FKOpt 1 2147483647 reference to time period 8 LIMITAREACONDITION NUMBER 10.0 Man 0 15 0 area related conditions 9 LIMITMANNERCONDITION NUMBER 10.0 Man 0 7 0 other conditions 10 LIMITLANECONDITION NUMBER 10.0 Man 0 7 0 lane related conditions 11 NUMLANES NUMBER 10.0 Opt 0 7 number of lanes the speed limit is valid for 12 LIMITROADCONDITION NUMBER 10.0 Man 0 15 0 road related conditions 13 TSYSCODE VARCHAR2(8) FKOpt reference to transport system 14 DESCRIPTION VARCHAR2(255) Opt description of speed limit 15 V NUMBER 10.0 Opt 0 999 speed limit - Sample for Belarus
- Sample pair from Belarus... 11 different scenarios for that integration unit. Maximum speed on segment 4278 is 90km/h. About 750'000 records in this L2S file fro Belarus (divide it by 2 to get the number of segments)
- Given data: a vehicles GPS trace with (x,y), heading, speed, timestamp.
- Question : did the driver exceed the official limit?
- Approach:
- use xMatch to reconstruct the driven geometry based on (x,y) and heading. This will give you segment IDs for each given position.
- use the side table to determine the maximum speed on the segments.
- compare the maximum speed with the driven speed
Bernd
