First the good news. Network Rail (NR), Britain’s infrastructure manager, says the project has enabled passenger operators to increase the number of services by 30% and cut journey times significantly by increasing the line speed from 177 to 200km/h and eliminating some bottlenecks. Capacity for freight traffic has been increased by 70%.

NR can rightly take credit for bringing the project under control both in terms of implementation and cost. When NR took over from Railtrack, the former infrastructure owner, costs were spiralling out of control towards a final, eye-watering price tag of £14.5 billion. NR’s final bill is £9 billion, which it says is £900 million less than it estimated when it took charge in 2003.

But even NR had its problems, with a major overrun of work a year ago at Rugby, a key junction on the line, which caused serious disruption to traffic. Rail users have suffered a decade of misery and inconvenience, especially at weekends when trains were diverted around work sites or replaced by buses.

The main reason why the project has taken 10 years to complete and cost so much, is a failure to maintain the line adequately for the level and type of traffic using it, coupled with several lost opportunities to modernise the route. Even now the project has not achieved some of its original objectives such as operation at 225km/h, and even higher train frequencies than available currently.

The southern part of the route was electrified in the 1960s, but some mechanical signalboxes were retained to save money, and have only now been replaced. Electrification of the northern section followed in the 1970s. At the same time, British Rail (BR) embarked on its ill-fated Advanced Passenger Train (APT) project which was supposed to revolutionise travel on the line with a fleet of 250km/h tilting APTs. But the project was killed-off in the early-1980s, leaving the route in limbo.

BR’s next attempt to modernise the route was in the early-1990s when it announced plans to buy a fleet of more conventional 250km/h trains and upgrade the line. In 1994 there was even talk of rebuilding the line for 300km/h operation, a ludicrous suggestion. Most railway engineers around the world agree that it is only economic and feasible to upgrade a conventional railway to 200km/h or to 225km/h if the original alignment is good. These plans fell victim to a budgetary cut.

In late-1997 Railtrack and the former Office of Passenger Rail Franchising (Opraf) agreed to a two-part plan. £1.35 billion was to be spent on renewing the core infrastructure - work that by then was long overdue - plus £150 million to increase the line speed to 200km/h by 2002. It was decided in 1998 - the launch year for the project - to increase the maximum speed to 225km/h, by which time the cost had risen to £2.2 billion.

Railtrack set great store on a revolutionary transmission-based train control system based on moving block signalling that would dramatically reduce costs by eliminating lineside signals and deliver a huge increase in capacity. But the system, which would be equivalent to Level 3 of the European Train Control System (ETCS), did not exist, so Railtrack awarded an open-ended contract to a consortium led by GEC Alsthom to develop it.

To launch a massive project based on a signalling system that has yet to be invented seems foolhardy to say the least, never mind awarding a contract to develop such a system without knowing what this is likely to cost. The development cost was estimated at the time to be between £500 million and £1 billion. Even now, 10 years later, ETCS Level 3 has yet to appear.

But a year later, Railtrack dropped the idea of moving block signalling and downgraded to ETCS Level 2, but even this proved impossible and by 2002 it was decided to install conventional signalling. NR has only recently launched its first ETCS pilot project in Britain.

By 2000, the cost of the project had escalated to £5.8 billion with a completion date of 2005. Railtrack was being accused by both the Rail Regulator and operators of dragging its feet with the project, which had so far achieved little on the ground. Railtrack forgot a cardinal rule of project management: you can plan until you are blue in the face, but at some point you have to turn plans into action, and then manage the work continuously.

By the time NR took over from Railtrack, not only had the Level 2 signalling gone, but along with it the idea of running trains at 225km/h, both of which had proved too expensive and time-consuming to implement.

The West Coast project offers a timely warning to infrastructure managers who may be thinking of deferring maintenance to save money; this is always a false economy. The money needed to maintain a railway must be in direct proportion to the loads and stresses put upon it. Failure to follow this simple rule leads to much higher costs in the long run, dwarfing any initial savings.