The main line acts as a 'spine' for several diverging branches, serving destinations such as Cambridge, Leeds, Hull, Sunderland and Lincoln, all with direct services to London.

In the early 1960s, steam was replaced by diesel-electric traction, including the Deltics, and sections of the line were upgraded so that trains could run at speeds of up to 100 mph (160 km/h).

The primary long-distance operator is London North Eastern Railway, but open-access competition on services to Northern England and Scotland is provided by Hull Trains, Grand Central and Lumo.

These races were ended over concerns over safety, but later the rivalry resumed in the 1920s and 1930s as both the LNER and its West Coast competitor, the London, Midland and Scottish Railway (LMS), produced ever-more-powerful express locomotives.

[15] Continuing demand for reduced journey times led British Rail to introduce a successor to the Deltics, the InterCity 125 High Speed Train (HST) between 1978 and 1979.

A short stretch of the ECML in the Newcastle area was electrified with a third rail in 1904, as part of the North Eastern Railway's suburban Tyneside Electrics scheme.

[21][20] During the period when Richard Beeching was chairman of British Rail, WCML electrification with a spur from Carstairs to Edinburgh was seen as possible justification for the truncation of the ECML at Newcastle.

[22] British Rail carried out electrification of the southern part of the ECML with 25 kV AC overhead lines from London King's Cross to Hitchin between 1976 and 1977.

[21] In the late 1970s, a working group of British Rail and Department for Transport officials convened and determined that, of all options for further electrification, the ECML represented the best value by far.

The Secretary of State for Transport Nicholas Ridley and Minister for Railways David Mitchell played a large role in the decision to proceed.

In total the electrification programme covered roughly 1,400 single-track miles (2,300 km) and required major infrastructure changes, including resignalling of the line from Temple Hirst Junction (near Selby in Yorkshire) to the Scottish border; the construction of new signalling centres at Niddrie, York, and Newcastle; the commissioning of ten new connections to the national electricity grid; and structure clearance and electrical immunisation works along the length of the line.

Through this process a special design of overhead wiring was developed for use on the visually-sensitive Royal Border Bridge, as well as the Croxdale and Durham City viaducts.

[24] As part of testing done to support safe operation the increased maximum speed, BR experimented in 1988 with using a fifth signalling aspect – flashing green – on the fast lines between Peterborough and Stoke Tunnel.

Upon encountering a steady green aspect the driver would reduce speed to no greater than 125 mph, and thus be ready to react to subsequent signals in the same manner as when driving a lower-speed train.

[36] Mining subsidence discovered in 2001 also necessitated the realignment of 1.8 km (1.1 mi) of line at Dolphingstone in East Lothian, between Prestonpans and Wallyford stations.

The new alignment takes the form of a gentle curve of up to 77 m (253 ft) towards the south, supported by concrete slabs and other ground stabilisation and reinforcement techniques, and is designed to avoid the need for a permanent speed restriction.

[43][44] On 26 September 1991, an InterCity 225 shortened electric locomotive train was authorised to reach speeds up to 140mph completing the London to Edinburgh journey in 3 hours 29 minutes.

The upgrade is set to include major track improvements and digital signalling, leading to higher speeds, reduced journey times and increases in seat capacity.

However, it is the most complex application yet; it is the first use in the UK of ERTMS on such a busy, mixed-traffic line, with freight, commuter, regional and InterCity services sharing as little as two tracks in the tightest sections.

There are currently no plans to retrofit ERTMS equipment to the InterCity 225 fleet, as they are expected to be withdrawn before the removal of the lineside signals; this means they will never reach their design speed of 140 mph (225 km/h) in service.

North of Grantham the line is double track except for quadruple-track sections at Retford, around Doncaster, between Colton Junction (south of York), Thirsk and Northallerton, and Newcastle.

[4] Plans for grade separating the crossing with a flyover or tunnel, which would increase capacity on both lines, have been proposed on several occasions but are complicated by costs and spatial constraints at the site.

By contrast, the West Coast Main Line crosses the Trent Valley and the mountains of Cumbria, with more curvature and had a lower speed limit of 110 mph (180 km/h).

LNER is operated on behalf of the Department for Transport by a consortium of Arup Group, Ernst & Young and SNC-Lavalin Rail & Transit, which took over from Virgin Trains East Coast on 24 June 2018.

[52] There are bottlenecks at the following locations: Railway operations are vulnerable during high winds and there have been several de-wirements over the years due to the unusually wide spacing (up to 75 m) between the supporting masts of the overhead lines.

The other cost-reduction measure was the use of headspan catenary support systems over the quadruple track sections – as employed in the Weaver Junction to Glasgow Electrification on the WCML during the 1970s.

Headspans do not have mechanically independent registration (MIR) of each electrified road and thus are more complex to set up, compared to TTC (twin-track cantilever)[57] and portal style support structures, during installation.

[59] The European Union Directive 96/48/EC, Annex 1 defines high-speed rail's minimum Speed Limit as 200 km/h (124 mph) on existing lines which have been specially upgraded.

Current plans include the following schemes: And on a more route-wide basis the following projects: The ECML has been witness to a number of incidents resulting in death and serious injury: The cuttings and tunnel entrances just north of King's Cross appear in the 1955 Ealing comedy film The Ladykillers.

[84] During 2009, the motoring show Top Gear featured a long-distance race, in which LNER A1 60163 Tornado, a Jaguar XK120 and a Vincent Black Shadow competed to be the fastest vehicle to travel the full length of the line from London to Edinburgh.