I would be surprised if someone's not suggested it / looked at it. But how do the economic, financial and political case(s) stack up? Will the Severn Beach line compete with or compliment other plans underway such as Metrobus, MetroWest and the Bristol Underground? Isn't it part of Metrowest in which case capacity will have been considered?
Strangely, or maybe not, MetroBust doesn't really touch the SVB line anywhere. The nearest it comes to it is passing below, on the M32. Atkins, in 2006, did suggest ripping up the line and replacing it with a guided busway. This met with stiff opposition, and they have had to wait until now to prove that guided busways are not necessarily cheap and easy to build. So other than on that existential basis, the SVB line neither complements nor competes with MetroBust. It is part of MetroWest, or at least will be when that happens properly, and should be part of routes to Bath Spa (or possibly even Westbury) and Portishead. The Bristol Underground will remain a pipe-dream until there is absolutely no room on roads for anything to move. The only reason I can see for it being mentioned is to try to persuade the locals that the councils and the new Metro Mayor actually have ideas, and that they can forget how long we have been talking about Portishead and rejoice that we want an Underground instead.
Routine cross-acceptance of tickets on public transport (not just put in place when one mode / operator is malfunctioning) would be too joined up ...
. No-brainer, but you would want to have a co-ordinated fare system. My understanding is that rail fares on "The Beach" are lower than bus fares at present, and indeed the low fares may also be a barrier to major investment in infrastructure such as an extra track as the rate of immediate return might be pretty poor.
The fares on the SVB must be the best value in terms of pence per mile anywhere in England. The fare was set at £3 return between Severn Beach and Temple Meads back in 2007, when the service was improved to the point of being usable by commuters.( My inner conspiracy theorist still thinks that improvement was done to prove that the line was not economic, and give Atkins their way after all!) A weekly ticket costs £9, which is less than a day's car parking in central Bristol. Between Clifton Down and any station to Temple Meads is a mere £2 return. The fares would cover the cost of the service if they were all collected, but that isn't easy at peak periods, given the large number of passengers, the short distance between stations, and the lack of
TVMs▸ or gatelines anywhere but Temple Meads. There have been proposals to raise the fares, but Bristol City Council no longer subsidise the service, and
GWR▸ may recognise that any increase could reduce the numbers actually paying for the ride. Extra track would enable extra trains, and so extra passengers, and would probably justify fare rises, but no-one seems to want to do that, at least not until MetroWest rail is up and running, and a more holistic approach can be taken.
The Severn Beach Line has been, for the past decade, its own feasibility study. The success it has had even with limited expenditure on improvements should be used to calculate new figures to judge cost against benefit for urban rail investment, because it doesn't look as though the current formulae fit the job.