Why is one longish stretch of straight track different speeds on different lines?

[Railwaysceptic]

Which came across as suggesting attitudinal failings were a cause. NR’s strategic route plans are available on line for an in-depth explanation of attitudes.

Quite obviously attitude plays an important role in decision making. When British Rail decided to limit mainline electrification to services out of Euston, those in charge of the East Coast Mainline decided to go for piecemeal improvements to speeds on their route. Their attitude was that one smallish project at a time was better than waiting forever for a major route overhaul to be authorised and funded. Similarly, deciding that secondary routes have no great commercial potential and that it is unproductive to increase their line speeds will be based at least in part on attitude. We already have examples of differences in attitude towards secondary routes between some open access operators and major TOCs. My point was and is that improvements to line speeds should not be limited to the busiest lines because towns and cities like Hull, Sunderland, Bradford and soon Rochdale do have the potential to increase railway total income and that their railway routes should also be improved.

There are two political aspects to this issue as well. The first is that our railway system is heavily dependant on taxpayer subsidy, and taxpayers in places like Hull and Sunderland - and Mansfield, Barnsley, Lincoln, Middlesbrough, Burnley among others - may feel that "levelling-up" entitles them too to have improvements to their railway provision. The second is that it's quite possible that after 2029 the House Of Commons will be dominated by Reform, a political party with an iconoclastic attitude to both Government expenditure and to the performance of people holding responsible positions in the public sector. Reform took control in County Durham a few weeks ago. The Durham Coast Line has two 45 mph speed restrictions between Sunderland and Hartlepool and some might argue that these should be removed. Reform also did well in Lincolnshire. Some people believe that the line speeds between Lincoln and Newark - and Newark and Nottingham! - are lower than appropriate.

 

[Cricketer8for9]

The taxpayers places you mention are subsidised by those in London and the South East.

 

[Grecian 1998]

As @Bald Rick has pointed out on this and other threads, what is technically possible is the sole operational concern. However, political and economic factors certainly play a part in creating the differences that are seen today.

There are lots of factors affecting linespeed on long flat sections of line that may not be obvious. For instance any open pedestrian or vehicle crossings will obviously require speed restrictions. Terrain may be a factor. I understand there are parts of East Anglia where long, straight sections of line have relatively low top speeds because the ground underneath is rather infirm.

Political and economic factors are that if there is a clear time benefit for lines with enough passenger traffic by improving the track layout to the extent that speeds can be increased, it is clearly easier to get the funding to do this. The ECML ironed out multiple bottlenecks from the 1960s to the 1980s e.g. at Peterborough in 1972. This allowed a gradual but continual decrease in journey times. The WCML route modernisation in the 2000s revised the layout at Rugby amongst others for the same reason. That route's decrease in journey times was rather more sudden.

Sometimes improving line speeds simply isn't realistic due to expense / political objections / disruption. There is a 25mph speed restriction just east of Southampton Central on a 2 track section of the SWML at Northam which I'm sure NR would love to remove - it must be a major bottleneck. However the number of properties you'd need to demolish to re-site the railway for a gentler curve and a higher running speed would be huge, and you'd have many, many years of planning appeals and litigation on top of the construction costs. The 40mph Morpeth curve on the ECML is likely similar.

Maintenance costs may be a factor as well. The higher the speed, the more TLC the track needs. I understand this is why fast lines out of London terminals are often under engineering positions in the late evenings and on Sundays, with traffic running on the slow lines - they need more maintenance. Salisbury - Exeter and Bournemouth - Weymouth are 85mph, whereas the busier sections of routes east of Salisbury and Bournemouth to London are 90mph. My understanding is that maintaining track at 90mph is notably more expensive than 85mph. Due to the frequent stops and lower passenger numbers, there isn't really any benefit in trying to improve the layout to increase speeds above 85mph.

The concern for NR is therefore simply what is a safe speed to run trains at. If there is a compelling business case to improve the layout so that higher speeds can be reached safely, that's great - but it requires funding, and that's a matter for the politicians.

I should state (as my be clear) I don't work on the railways, so those with greater technical knowledge may want to correct me.

 

[Bald Rick]

Political and economic factors are that if there is a clear time benefit for lines with enough passenger traffic by improving the track layout to the extent that speeds can be increased, it is clearly easier to get the funding to do this. The ECML ironed out multiple bottlenecks from the 1960s to the 1980s e.g. at Peterborough in 1972. This allowed a gradual but continual decrease in journey times. The WCML route modernisation in the 2000s revised the layout at Rugby amongst others for the same reason. That route's decrease in journey times was rather more sudden.

Both the ECML and WCML have had numerous linespeed improvement projects, progressively, more or less since they opened, in various different guises. Some obvious, some less so.

== Doublepost prevention - post automatically merged: 5 Jun 2025 ==

My understanding is that maintaining track at 90mph is notably more expensive than 85mph.

That’s not strictly true. The only differenc is track inspection frequency, which is a fraction of maintenance costs. My post above (29) explains one such example.

 

[Railwaysceptic]

The taxpayers places you mention are subsidised by those in London and the South East.

Tell me about it! I live in London.

I made my living for several years by wheeling and dealing on the phone with companies all over the U.K. and abroad. I was always acutely aware that my career in London was dependant upon people and companies outside of London. I do not resent some of London's cash being re-distributed around the country.

 

[brad465]

Both the ECML and WCML have had numerous linespeed improvement projects, progressively, more or less since they opened, in various different guises. Some obvious, some less so.

The two most recent big ones I can think of are the Kings Cross remodelling in 2021, which increased both the entry/exit speed from the platforms and the linespeed through the Gasworks' tunnels, while on the WCML the Carstairs' remodelling increased the mainline speed through the station, but crucially the entry/exit speed for Midcalder line movements in all directions.

 

[The Planner]

Back in the day when I was involved in train planning (late 1970s/early 1980s), there were five track maintenance categories for BR lines:

A - maximum speed 90 or above
B - maximum speed 75-85
C - maximum speed 55-70
D - maximum speed 30-50
E - maximum speed less than 30

The maintenance budget for each category of line increased incrementally according to the speed category. Not sure whether this is still the case. @Bald Rick will be able to tell us.

If you have a steeply-graded section of otherwise well-aligned main line, it makes sense to have a lower speed limit on the uphill line - if trains are unlikely to be able to reach a higher speed - in order to save money on maintenance. As well as the High Wycombe-Saunderton section already quoted, another example that springs to mind is Huddersfield-Marsden, which is 70 on the Up and 85 on the Down.

Do a search on NR/L2/TRK/001/ and you will find an older graph on the track categories on page 7, the inspection regime on page 8. Basically 1A to 6 based on speed and tonnage as @Bald Rick noted.

 

[Cricketer8for9]

Tell me about it! I live in London.

I made my living for several years by wheeling and dealing on the phone with companies all over the U.K. and abroad. I was always acutely aware that my career in London was dependant upon people and companies outside of London. I do not resent some of London's cash being re-distributed around the country.

I’m not one to argue, at least all the time, that money should stay where it’s made. We are a country after all, not a series of countries. But the reality needs to be understood.