The introduction of smartcards generated a rich data source about how and when people travel, providing us with a time and location of a journey.
However, unless operating in a closed or fully gated system (such as the London Underground), there is often no information about where the person travels to.
To help with this, we are undertaking a programme of work to develop a 'reverse journey matching algorithm', providing members with a tool to help analyse their smartcard data.
What is reverse journey matching?
Reverse journey matching is the process of inferring the alighting point of a journey. Smart card data gives us detailed information about where and when a person starts their journey, but nothing on where they get off the bus. When a person makes two or more trips on a day, we can use a process of ‘reverse journey matching’ to infer where the passenger was likely to have got off the bus. Knowing where the subsequent journey starts, we can make a number of reasonable assumptions about where the person is likely to have alighted their previous journey.
The initial phases of this work have allowed us to prove that a reverse journey match could be achieved for a high proportion of bus journeys, with a longitudinal approach being used to help fill in any gaps (such as where only one journey is made in a day so a reverse journey match is not ordinarily possible).
We have then developed an online tool to enable our members to upload bus journey data and undertake basic analysis.
We are now undertaking a final phase of work to further develop the analysis capabilities of the tool, allowing it to provide automated answers to some of the key questions
- How many trips have been made?
- How many smartcards have been used?
- How many trips did each smartcard make?
- What are the most common origins/destinations, by day, time of day, etc.?
- How do the above travel patterns change over time?
This work is an exclusive benefit for our full members.