TBST Trafik, Bygge, og Bolig -styrelsen
Tablesalt is a package for analysing Rejsekort Delrejser data. Delrejser, or partial trips, is a dataset created at Rejsekort that contains a record for each check-in or checkout at a blue dot terminal.
This delrejser dataset is not the raw data recorded at a terminal in a station or on bus, it is processed by Rejsekort to form "trips".
The rejsekort system itself records the sequence of transactions at terminals and associated timestamps for the purposes of revenue collection and follows the Danish public transport fare system. It is not designed with trip analysis in mind.
If you purhase a 2 zone cash ticket from a machine or a kiosk in Sjælland, that ticket is valid for 75 minutes. It is not only valid for a single journey, but for any number of trips you can make in those 75 minutes, provided you do not go further than two zones away from the zone you start in. The rejsekort system mimics these conditions with the caveat that you are to check-in when you start your journey, when you transfer transit modes and checkout when your journey is finished.
If you're travelling using a rejsekort and you travel more than two zones the system recognises you have and charges you accordingly. For each zone distance the validity time increases and should you not travel further away from you destination, you can make any number of trips within the time period given by:
| zones | minutes |
|---|---|
| 2 | 75 |
| 3 | 90 |
| 4 | 105 |
| 5 | 120 |
| 6 | 135 |
| 7 | 150 |
| 8 | 165 |
The processed data groups all of these transactions for a user using these zone distance and temporal validty thresholds and assigns a unique tripkey. That definition of a trip is not necessarily equate to a transport analyst's definition of a trip, be that trip-based, tour-based, activity-based etc.
This is where tablesalt aims to help out by being able to split trips up and validate operators and modes.
The delrejser data produced by Rejsekort, while comprehensive still contains errors in leg operators and timestamp/sequence mismatches. Tablesalt provides functions and classes to tackle these errors.
Given that the rejsekort system relies on users actually checking in and out where appropriate, the delrejser data contains incomplete trips. Methods are provided to deal with these as well.
Using tablesalt you are also able to produce various origin-destination matrices of rejsekort trips, as well as find operator zone work per trip and to model other types of tickets