I'm not an expert by any means but you don't seem to know much about railway planning.
New railways and services create new traffic, usually in excess of feasibility studies. When the Borders Railway (former Waverley line from Edinburgh to Carlisle) was reopened between Edinburgh and Tweedbank the passenger figures were about 5 times the projections.
I was one of the people who though Grand Central would fail because I thought there'd be no demand for rail services from Sunderland to London but I was wrong. Grand Central created new traffic. As I said earlier reopening Sunderland - Durham is virtually impossible but if was done the trains would be chock a bloc because it would create new journey opportunities.
These are new lines though not duplicate services. I've nothing against Sunderland to Durham though, but more for the intermediate stations as much as anything. Some sizeable towns like Houghton etc. Most the suggestions here are extending services from Newcastle to Sunderland and nothing more and it's just pointless. I do think there could be scope for making Grand Central more frequent though even if it was just shorts to York, or maybe some to Leeds instead running from their Colton depot.
If Sunderland wants more trains to elsewhere, the biggest hinderance is Teesside imo. If were being serious about moving people to cars then the ideal thing would be to build some form of tunnel / bridge from Seal Sands across to Teesport. It would be expensive but arguably better than building another road bridge.
Means you could open York - Middlesbrough - Hartlepool - Sunderland trains and imo the demand would be there which isn't possible currently. The trains from Hartlepool to Middlesbrough currently are like running on a cart horse, the timings for the 21st century is just appalling with a detour around Stockton not serving anywhere and Eaglescliffe is a terrible station for London trains.
I disagree with most of what you say.
1. The city centre of Sunderland currently has around 3,000 people living in it, very soon it's going to be at least double to 6,000, but possible up to 10,000.
2. No-one from London need to be in a place like Sunderland? Maybe apart many companies like Hayes Travel which have their HO in the centre of Sunderland where staff frequently travel to, from all around the country, that's one of many Sunderland located businesses.
3. Within the next decade (about an extra 2,000 as early as next year when the L&G offices open) up to 10,000 office workers, based in the City Centre.
4. New start ups like the new Film studio's at Crown Works for major Film and TV attracting people from all over the world.
5. It's in the City Plan for continued investment in the Port of Sunderland, most of the off-shore supply ships that are increasing using Sunderland use it for crew changes, they need to get to Sunderland somehow, I wonder how they might achieve that?
6. This is just the beginning of the re-emergence of Sunderland.
As you can see future demand for better services to Sunderland should become a reality. It's no good planning
But there's already services to London, how many more services are realistically needed? There's also soon to be 6 trains an hour to Newcastle which is a bloody excellent service, ignoring the local rivaries. Some parts of London don't get that level of service so anyone wanting to go to places like Pallion have that direct link, not to mention the direct link to the airport aswell.
Personally Sunderland is well served imo for going distant places. It's the local routes that are the problem even if it does mean having to connect elsewhere. There's a lot of places with a much worse service.
How do you know there is ‘no demand towards Sunderland’. It’s another ludicrous statement from you on this topic.
I am telling you that I am asking for better connections from Sunderland - and judging by others posters on this topic there certainly seems to be interest - so even on this tiny sample your statement is patently wrong.
Current demand from Sunderland is being mopped up by Newcastle and, to a lesser extent, Durham.
The franchise system is purpose-made to support broader economic development by supporting non-commercial services to the benefit of the wider area. Every single franchise around GB includes such services and has done since privatisation in the 1990’s. (I bet British Rail did that before then too).
I’m saying that it’s time for Sunderland to stake its claim for transport support towards its economic development.
Do you use the trains every day, as if everyone use the trains 2 times a year then who's using them every other day. The ECML works because people are using the trains from Sunderland aswell; take Sunderland away then the ECML would start to struggle aswell. There's also a very sizable chunk of people who travel locally on the ECML trains, especially between Durham and Newcastle; there's no local flow between Sunderland and Newcastle as the Metro already covers it.
So unless suddenly half of Sunderland needs to go Leeds and London every day then who's going to be using these? Grand Central also has this benefit that it serves Teesside aswell. Take away Teesside / Hartlepool and it wouldn't exist either and that's over 600k people. Unless you build a line to Durham or push them down the Durham Coast then it won't work omit either and it'll be dead like the LNER service every day.
See the first post for the only genuine thing that would get intercity or regional trains to Sunderland but it means working out of area.