That 2% figure is highly misleading and sadly repeated by both politicians and the media. It comes from UK total journeys that passengers make of which 46% are on foot and 2% by bike. The appropriate figure of journeys that can be made by rail is 9% of the total, with 90% road and 1% air.
All these figures that include walking or public transport, even car use, are IMHO misleading.
How, for example do they count my travel. Depending on my role at the time, a day could involve walking to the railway station, train trip to my depot, driving the company van. Walking from the van to the site of work. Then return.
Or, drive my car to the railway station. Get the train to London (split ticket because I had a season ticket for part of the trip). Change to the Tube. Walk to the office where I attended a meeting. And return. Often having to change trains on the way back.
Also, how long do you decide to allow between parts of a journey to count them as separate? Especially if you have to pop in to somewhere or meet someone in between the different journeys?
And just to complicate matters further, there are multiple different routes I use when walking or driving. And I used multiple different trains as the time I needed to arrive varied.
Only very occasionally would anyone on a train hand out survey cards. And then the answer boxes often only allowed simple answers...
And of course at least some of the statistics are most likely based on a "representative" sample. I mean, just look at the discussion on here about split tickets and how the number of journeys are counted...
As usual, statistics if some of the relevant details are not included, can be rather misleading.