Last year’s confidence and supply agreement between the Conservative party and the DUP saw 40 per cent of the Northern Irish party’s £1bn price tag allocated to infrastructure. Although there is, at the time of writing, no functioning government in the North to spend it, where could £400m be best used?

Northern Ireland is not, geographically, a large place. The six counties are inhabited by under 2m people and, to use a comparative metric that anyone who has sat in a high school geography lesson may remember, the North is less than half the size of Belgium. Belfast and Derry, Northern Ireland’s two major urban centres, are only a 70 mile drive apart. On the face of it then, an injection of cash into infrastructure should be relatively straightforward.

Yet the Belfast Rapid Transit system is the only notable public transport infrastructure currently being developed in the North. That takes the form of a web of connected bus lanes, as well as investment in a new bus fleet for use in them, that aims to cut car use in the heavily congested city.

One way to spend the money might be to tame the Irish Sea. Democratic Unionist Party MP Sammy Wilson claimed back in January a bridge between Northern Ireland and Scotland was “feasible” and would be a “much needed alternative” to the current ferry route. Unsurprisingly, he isn’t the first to notice that Northern Ireland’s east coast is only 20 miles from Scotland.

But while some MPs dream of bridges across the sea, interest in more useful infrastructure is less forthcoming. Take the NI Railways service, which despite the name only covers a fraction of the North. A simple glance over a map shows how fractured coverage is.

Even where the trains do run, the service is hardly efficient. The Belfast-Derry journey takes over two hours, which doesn’t compare well with the current London-Birmingham fast service, which covers almost twice the distance in 1hr22. Belfast City Airport, which last year handled 2.5m passengers, is serviced by Sydenham Station – but only via shuttle bus, which you have to request, or via the verge of the A2.

Meanwhile there is no train at all to Belfast International Airport: instead, an expensive taxi or a bus through the Northern Irish countryside is required. It may be scenic, but it isn’t good infrastructure.

That said, NI Rail saw 14.2m  passenger journeys last year, compared to 11.5m in 2012-13: the problem isn’t that there is no demand for infrastructure, simply that no one has bothered to build it.

It is a similar story with roads. Belfast and Derry are only a 70 miles apart, yet there isn’t a direct, or even indirect, motorway link between the two. In fact, there are only 60 miles of motorway in the entire North: all are in the east, almost exclusively focused on Belfast.

Northern Ireland is, of course, not the only part of the UK poorly supplied when it comes to transport. Anyone reading this who lives in the North East of England or who relies of commuters trains around Manchester, for example, will have experienced similar problem. So what makes Northern Ireland special?

Well: for a relatively small geographical area, there is a striking polarisation in the provision of transport. Not only is there an overall lack of infrastructure, but what does exist is overwhelmingly concentrated in the east. To take one instructive statistic, 51 of Northern Ireland’s railway stations are located east of the River Bann, the traditional dividing line between east and west.

This divide isn’t an accident: rather, it’s a legacy of the North’s sectarian history. The east has been traditionally unionist, the west nationalist, and there has been a strong bias in economic power and investment towards the former. As analysis from Northern Irish regeneration advisor Steve Bradley shows, the main rail and road networks are almost exclusively confined to areas where Protestant are more common than Catholics, and where the DUP holds political power.

So, if the North does come under direct rule from Westminster, there are some fairly obvious gaps in the transport network that could do with being filled – based on the needs of citizens, rather than their background or voting preference. But with the open question of the Irish border hanging over us – something which brings implications for cross-border travel along with everything else – the chances of that appear slim.