Oxford's centre faces rigid space constraints that, even if private motor vehicles could be excluded, create an apparently insurmountable conflict between livability and active transport modes on the one hand and public transport on the other. As a long-term solution, I propose that all inner-city public transport be provided by a mini-bus (or tram) shuttle loop, connecting to city and intercity bus services at interchanges at the Plain (or the bottom of South Park), St Aldates, the railway station, and St Giles.
Narrow Medieval Streets
One of the common objections to urban transport plans in Britain — weirdly, most commonly to proposals to build infrastructure for bicycles, one of the more space-efficient transport methods — is the existence of narrow medieval streets.
Now mostly this is just wrong. Most British towns and cities have only tiny medieval cores, if indeed they have any, and most of those had whopping big "relief roads" built through or around them in the 1970s. And indeed most big cities that still have medieval streets have already pedestrianised them.
Oxford is, however, one of the few places this is actually an argument with some weight (though you don't have to go far to find places such as St Giles or Broad St where the problem is clearly not space but misallocation of space). Oxford has a medieval core that does have genuinely narrow streets and it lacks any real inner ring road. There is no feasible way of obtaining more space on bottlenecks such as Longwall and Worcester Streets, or on High St and St Aldates. Donnington Bridge and Marston Ferry Rds provide a kind of partial inner ring, but proposals for a southern road through Iffley Fields and Christ Church Meadow, or a western one through Portmeadow, were considered and rejected in the 1970s.
This makes central Oxford a, if not the, bottleneck in any city-wide transport plan, and necessitates solutions that would not be appropriate for most cities.
Motor traffic generally is slow due to congestion, and because public transport (both intra-city and, apart from the railway, inter-city) is provided by buses that mostly share roads with private motor vehicles, it too is slow. Even in the areas from which private motor traffic has been excluded (at least at some times of day), such as High St and George St, buses are still delayed by having to overtake one another and find stopping spaces, as well as having to negotiate people walking and cycling. The bus services are also focused on getting people into and out of the centre, and provide poor options either across the centre or around it — try, for example getting from Christchurch to the Museum of Natural History, or from Cowley to Summertown.
The central city is a relatively unpleasant place to be, because it is hostile to pedestrians. This discourages tourists but also reduces its value for residents and regular visitors. And Oxford has dangerous air pollution levels.
The city centre is too threatening for most potential cyclists, even though almost all of Oxford is within reasonably comfortable cycling distance of the city centre. A significant fraction of residents commute by bicycle, but that could be a fair bit higher and the share of utility cycling is clearly much lower.
The county council recently released its transport plan out to 2035, which included some ideas out to 2065. Looking at that inspired me to think about what a long-term solution to Oxford's transport problems might be.
Oxford is still growing. There are new developments at West Barton, the Northern Gateway, Oxpens, Westgate and so forth, while there is still new housing going in as infill or redevelopment of retail and light industrial sites, as well as attic conversions to add rooms to existing houses (there were five this summer in my street alone). The universities are keen to house more students, businesses see more tourists as desirable, and there's clearly demand for more residential housing.
Obviously nothing is uniform, and growth predictions can be notoriously wrong, especially for transport. But let's imagine, as a kind of baseline, everything scaled up by 20% — 20% more cars, 20% more buses, 20% more bicycles, 20% more taxis, 20% more delivery vehicles, and 20% more pedestrians all trying to get through, or around, central Oxford.
Now this is, if not actually impossible given the space available, a mind-bogglingly terrible prospect. So now let us assume that the most obvious measure has been taken, to remove the least space efficient mode, private motor vehicles. I'm envisaging a situation where the only access to the city centre for taxis or private motor vehicles is for disabled users. At least Longwall and probably Worcester St are closed to motor traffic, perhaps there's a congestion charging scheme, maybe a ban on through traffic using the Botley Rd (Richard Mann's idea), maybe the inner sections of the arterial routes have been made into one-way pairs (following Danny Dorling's suggestion). I'm also going to assume that we have solved the problems for buses getting into Oxford from outside and that they can get to central Oxford in reasonable time from the park and rides, or from towns such as Witney.
Now, instead of a uniform 20% increase, we might be looking at a 90% decrease in private motor vehicles alongside a 50% increase in the number of buses and maybe a 30% increase in the number of people cycling, along with our baseline 20% increase in people walking, vehicles loading, and so forth. In this scenario, the situation in the inner city is still absolutely dire -- just consider George and High Sts, from which private motor vehicles are largely excluded already.
Not a Solution
The County Council's proposal is for bus/bicycle tunnels to be built under Oxford. This was first mooted at a time when roadworks were causing traffic delays, so I assumed it was floated simply as a distraction. But then it actually appeared in the Longterm Transport Plan... This is such a mad idea, on even cursory inspection, that it seems to basically be saying: "Oxford's transport situation is dire, but the only plausible solutions will really annoy the people who elected us, and we don't really care about Oxford itself so we'll just give up".
The cost would be stupendous. The archaeological work alone would run to tens of millions of pounds, and since Oxford is built on alluvial gravel the engineering would be a nightmare. This could conceivably cost a billion pounds, once the costs of land acquisitions to fit in ramps to access the tunnels was included.
But it's an inherently flawed solution, regardless of cost. It would only assist those trips that followed the routes of the tunnels. And most people riding bicycles and catching buses want to get off at destinations inside the city, which would require a complex mass of elevators and lifts.
My thinking is along the same lines as that in the city council's response to the county's 2035 plan. From which I take, in particular, the following paragraphs (with my emphasis):
"There should be a comprehensive review of the bus network in the city with a view to minimising the lay-over space required in the centre but also the need for buses to pass through the very centre of the core. Consideration should be given to implementing an electric shuttle mini-bus that will connect transit hubs with key destinations"
"only vehicles appropriate to the city centre environment run on the 'inner orbital' routes with the larger vehicles identified in the Strategy only operating on the radial routes. Buses in the city centre need to be of human scale, not intimidating"
First of all, as mentioned above, the least efficient transport modes have to go from the city centre. That means all private motor vehicles and taxis, with exceptions only for disabled users and what few residents there are in the affected area, and time- and weight-constraints on loading access. For simplicity, I'm envisaging a uniform scheme covering the entire central city. This is going to create howls of protest, of course, and would probably be the major sticking point in actually implementing this.
All buses and coaches, inter-city and intra-city and tourist, would terminate at bus stations on the edge of the centre: at the train station, St Giles, the Plain, and St Aldates/Speedwell St. (Arguably inter-city buses should terminate at a big bus station somewhere on the ring road, to allow Oxford to be a node in a national fast coach network, but this proposal is utopian enough already, without throwing in a fix for the UK's broader transport problems.) All transport between those bus stations, and around the inner city more broadly, would be provided by an electric mini-bus service running in a loop (Vienna).
As well as being small in order to be compatible with the human environment, such a shuttle would need to be single-stream and low latency, which means small, fast-loading buses running on a very rapid schedule. To reduce delays to an absolute minimum, the service should be free. The council(s) could fund this by making operators of connecting services contribute, levying tourist operators, and/or tithing the university.
The interchanges would have to involve as little walking as possible and be comfortable and convenient. I envisage no problem at St Giles or the station, where there is ample space (assuming the car parking goes), and suggest that these two would be the terminuses for inter-city coaches. St Aldates and the Plain pose bigger problems, perhaps especially the Plain, which has to be made walking and cycling friendly as well. To this end, I propose that Magdalen Bridge carry no other motor traffic at all, other than emergency vehicles, with loading and disabled access to the centre by other routes. The shuttle would terminate outside the current Sainsburys, interconnecting with buses going around the roundabout. (A reversible tram would be an advantage here.) Alternatively, the shuttle could perhaps be routed further, looping around Rectory Rd and Marston St, or the bottom end of Southpark could be repurposed as a bus station.
There would be options for routing a bus shuttle between the four interchanges. A tight enough loop, running say St Aldates, High St, the Plain, Longwall, Hollywell, Broad St, George St, Hythe Bridge St, Park End St, New Rd, Speedwell St, could conceivably be one-way. A larger loop might be too long to be one-way, but could serve a broader range of destinations (the science area of Oxford university, possibly Jericho). Two differently routed loops running in different directions would be a possibility.