For plausibility purposes the correctness of the path stated by the passenger is verified for each survey data. By comparing each survey data with the timetable information of the Visum network model, implausible routes can be identified and corrected by replacing the corresponding lines (or line routes or time profiles) with plausible lines (or line routes or time profiles). Furthermore, additional data is added to each data record, such as times of departure and of arrival, travel time and trip distance, used lines and walk links.
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Note: The boarding and alighting stops stated in the interview data records must exist in the analyzed network. If this is not the case, the record in question is ignored. If one of these stops is deleted after reading survey data from file, all paths from/to these stops will get lost. |
Plausibilization: Basic approach
As a rule, the plausibilization includes the following steps.
1. Validity check of the survey path leg (Image 171)
2. Validity check of the pre-survey leg (Image 172)
3. Validity check of post-survey leg
For each of these steps, the validity check can be run several times, in order to check the survey data successively with hard-to-meet criteria, which become easier and easier with each run.
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Note: In single-row survey data records, the pre-survey leg as well as the post-survey leg may consist of one or two path legs each (User Manual: Format of a single-row survey file).
In multi-row survey data records, the previous section as well as the post-survey leg may consist of any number of path legs (User Manual: Format of a multi-row survey file). |
Validity check of the survey path leg
Image 171: Validity check of the survey path leg
* In case of multiple vehicle journeys, the one with the minimum sum of run time and wait time is chosen.
Validity check of the pre-survey leg (example with 1 or 2 pre-survey path legs)
Image 172: Validity check of the pre-survey leg
* In case of multiple vehicle journeys, the one with the minimum sum of run time and wait time is chosen.
Validity check of post-survey leg
The validity check of the post-survey path leg(s) is performed accordingly (Image 172).
Status IDs for the plausibilization quality
In a result file and also in lists (PuT paths and PuT path legs), a status ID (range 0...10) describes the quality determined by validity check and plausibilization for each survey record:
- for the surveyed path leg E in (Table 194)
- for the pre-survey leg V in (Table 195)
- for the post-survey leg N in (Table 196)
- for the entire survey data record G in (Table 197)
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Status indicators for the surveyed path leg (E) |
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0 |
Not yet checked |
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Plausible |
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Plausible: Corresponds to the specifications (1) |
A vehicle journey could be found in the surveyed time profile (or surveyed line route or line, depends on preciseness of input data), which connects boarding stop and alighting stop of the surveyed path leg and starts within the time tolerance interval defined for the time of departure from the boarding stop. |
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Plausible: Deviating line route or time profile (2) |
A vehicle journey could be found in another time profile (or line route) of the surveyed line, which connects boarding stop and alighting stop of the surveyed path leg and starts within the time tolerance interval defined for the time of departure from the boarding stop. |
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Plausible: Deviating line (3) |
A vehicle journey could be found in a time profile (or line route) of another line, which connects boarding stop and alighting stop of the surveyed path leg and starts within the time tolerance interval defined for the time of departure from the boarding stop. |
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Plausible: One path leg requires an additional transfer (5) |
For the surveyed path leg, an indirect connection could be found by timetable-based search (shortest path search) which departs from the boarding stop within the tolerance interval defined for the departure time from this stop and includes at least one transfer (and walk links, if applicable). |
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Not plausible |
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Unplausible: No direct line route found (7) |
Implausible, because none of the line routes (which are valid due to current parameter settings) connects boarding stop and alighting stop and connection search is not permitted either. |
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Unplausible: No departure at specified time (8) |
Implausible, because the time profiles of the line routes (which are valid due to current parameter settings) connecting boarding and alighting stop do not include a departure within the time tolerance interval defined for the time of departure from the boarding stop and connection search is not permitted either. |
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Unplausible: No connection found (9) |
Implausible, because no connection from boarding to alighting stop starting in the given time frame could be found during connection search calculation. |
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Status indicators for the pre-survey leg (V) |
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Untreated (0= |
Does not exist |
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Plausible |
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Plausible: Corresponds to the specifications (1) |
A vehicle journey could be found in the pre-survey leg time profile (or pre-survey leg line route or line, depends on preciseness of input data), which meets the condition defined for the permitted time span. |
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Plausible: Deviating line route or time profile (2) |
A vehicle journey could be found in another time profile (or line route) of the pre-survey leg line, which meets the condition defined for the permitted time span. |
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Plausible: Deviating line (3) |
A vehicle journey could be found in a time profile (or line route) of another line, which meets the condition defined for the permitted time span. |
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Plausible: Unplausible pre-survey leg or post-survey leg replaced by direct connection (4) |
A direct vehicle journey from OriginStop to BoardStop with a shorter journey time (Factor • Journey time of Direct connection + constant < Journey time of pre-survey leg) compared to the plausible (multi-part) pre-survey leg could be found and is used instead. |
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Plausible: One path leg requires an additional transfer (5) |
Replacing at least one of the pre-survey path legs by an indirect connection which was found by timetable-based connection search (incl. transfer(s) and walk link(s), if applicable). |
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Plausible: Unplausible pre-survey leg or post-survey leg replaced by shortest path (6) |
Replacing the implausible (multi-part) pre-survey leg from OriginStop to BoardStop by a connection with an arrival time matching the departure time of the survey line from the BoardStop. |
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Not plausible |
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9 |
Implausible, because no path leg (or sequence of path legs) could be found meeting the given validity check criteria. |
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Status indicators for the post-survey leg (N) |
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Untreated (0) |
Does not exist |
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Plausible |
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Plausible: Corresponds to the specifications (1) |
A vehicle journey could be found in the post-survey leg time profile (or post-survey leg line route or line, depends on preciseness of input data), which meets the defined for the permitted time span. |
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Plausible: Deviating line route or time profile (2) |
A vehicle journey could be found in another time profile (or line route) of the post-survey leg line, which meets the condition defined for the permitted time span. |
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Plausible: Deviating line (3) |
A vehicle journey could be found in a time profile (or line route) of another line, which meets the condition defined for the permitted time span. |
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Plausible: Unplausible pre-survey leg or post-survey leg replaced by direct connection (4) |
A direct vehicle journey from AlightStop to DestStop with a shorter journey time (Factor • Journey time of Direct connection + constant < Journey time of post-survey leg) compared to the plausible (multi-part) post-survey leg could be found and is used instead. |
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Plausible: One path leg requires an additional transfer (5) |
Replacing at least one of the post-survey path legs by an indirect connection which was found by timetable-based connection search (incl. transfer(s) and walk link(s), if applicable). |
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Plausible: Unplausible pre-survey leg or post-survey leg replaced by shortest path (6) |
Replacing the implausible (multi-part) post-survey leg from AlightStop to DestStop by a connection with a departure time matching the arrival time of the survey line at the AlightStop. |
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Not plausible |
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Unplausible: No connection found (9) |
Implausible, because no path leg (or sequence of path legs) could be found meeting the given validity check criteria. |
Table 196: Status indicators for the post-survey leg
