I'm not trying to reform transport in Oxford for myself. Personally, I find Oxford remarkably easy to get around, and indeed one of its attractions for me has always been that, while it has the "cultural capital" of a city many times its size, it feels like a village because getting around it is so easy.
The key thing here is that I'm reasonably fit and confident, and will happily cycle almost anywhere in the city. This means I have a fast, reliable, convenient and cheap option for most trips. I am similarly capable of negotiating the obstacles Oxford throws at pedestrians. On top of that, we are well enough off that we can afford to own a car, to pay parking fees or bus fares when we need to without thinking about them, to have a tandem bicycle that makes cycling anywhere with a child possible, and to live not too far out of the centre.
But for many people things are not nearly so pleasant.
Most people — I would estimate two thirds — aren't comfortable cycling around Oxford. They either don't cycle at all, do it only recreationally in parks or touring, or only cycle limited routes at restricted times. They are not so fit or confident, face higher risks than me, are less able to cope with stress, have children and no easy option for cycling with them, or have to deal with other obstacles. This leaves them facing an often much less attractive range of choices.
My commute is about 12 minutes on a bicycle, but someone unable or unwilling to cycle it faces much less appealing options. Including walking at either end, the bus might take 30 minutes if all goes well, but could take significantly longer in peak hour — and an annual bus pass costs nearly £600. And walking would take maybe 45 minutes. (Looking at the census data, of the 632 people commuting from my census area to central Oxford 260 cycle, 160 walk, 144 take the bus, and 60 drive (in 52 vehicles). But commuting figures flatter cycling rates: they don't cover children or the elderly, and people are less likely to cycle less regular shopping or socialising trips.)
Oxford's bus system is pretty good by UK standards, but mostly has to deal with the same congestion as private cars. And it doesn't work so well if you're not trying to get into or out of the centre. Friends bringing children to our house for playdates, for example, from Lye Valley or Headington Quarry, face awkward journeys. Trips that take me, with Helen in a child seat or on the tandem, 10 or 15 minutes, for them involve walking and roundabout bus routes; it only takes a missed bus or traffic congestion for them to be facing hour-long trips. (The "Pickmeup" on-demand bus service might alleviate this problem, but would still leave my friends paying £10 for an afternoon visit.)
For many people, walking even to local destinations can be problematic. Oxford's residential streets include both cramped "parking lots", which force people walking into the middle of the carriageway, and broad rat-runs with too much motor traffic going too fast, which can be tricky to cross. I face only a slight rise in stress negotiating these streets, but people who are visually impaired, slower-moving, accompanied by small children, in wheelchairs, or just more nervous will find them much more challenging. I can see why many people won't let their children walk or cycle to nearby schools. Similarly, if you're pushing a stroller, using a walker, otherwise mobility impaired, or unfamiliar with Oxford, then the city centre suddenly becomes a gauntlet of narrow crowded footpaths, buses and bicycles, hostile crossings, and other unexpected hazards.
And then there are the people stuck in traffic, in cars or buses, getting into and out of Oxford every day, many of them also facing congested trips getting to or from Oxford.