Rail is the only mode where real progress is being made in increasing maximum speed. In contrast, other modes are stuck or even going backwards. The maximum speed of civil aircraft has already peaked at Mach 2, and with Concorde now a museum piece, air travel is stuck at sub-sonic speeds of around 900km/h. With fuel prices as high as they currently are, there is little likelihood of any improvement anytime soon.

On the roads, widespread introduction of evermore restrictive speed limits, coupled with increasing congestion, and rapidly-escalating fuel prices, have combined to make road transport slower, more unpredictable, and more expensive. Indeed, many cities are now pricing cars off their roads.

This is resulting in a surge in demand for urban rail services and a need for operators to increase capacity. Technology is coming to the rescue in the form of communications-based train control (CBTC), which enables fixed-block signalling to be replaced by moving block, and full automation of a metro with driverless operation the ultimate prize. Path, which operates the metro linking New York and Newark, estimates that CBTC will give it a 20% increase in capacity.

Last month's conference on CBTC, staged by Global Transport Forum in Stockholm, highlighted many "dos and don'ts" of CBTC, not to mention some sound advice on how to manage complex projects and the implications of introducing new technology.

Installing complex systems such as CBTC, which will result in a new way of operating a railway, have far-reaching ramifications for not only train operations, but also maintenance and staff. Failure to address these issues at the outset threatens to put the metro or railway through a lot of expense and pain for little or no benefit.

For example, CBTC enables a metro to move to unattended operation (UTO), which allows it to operate far more flexibly. Train frequency can be increased quickly to respond to a sudden surge in demand, such as the end of a football match, as the operator does not have to worry about whether enough drivers are available. Existing drivers can be redeployed to much more productive and interesting jobs. But it is surprising how many metros fail to negotiate new terms with staff and unions before starting to install CBTC in the faint hope that the issue can be resolved at a later date.

As Mr Krister Jonsson, head of metro, with Greater Stockholm Local Transport (SL), pointed out, it is vital to ask questions before going out to tender. For example, how much of the work should the metro try to do itself, and how much risk should the contractor be asked to take on? As Jonsson says, leaving all the risk to the supplier is a very expensive way to buy a lot of insurance that you don't actually need.

Jonsson also recommends setting up a project steering team, a project managing team, and a project organisation. Mr Aurelio Rojo Garrido from Madrid metro also recommended having technical teams working in parallel while at the same time minimising administration.

It is also important to decide whether to purchase "off the shelf" technology or a system with bespoke features, bearing in mind the cost implications of doing so. If you take the latter path, then the metro needs to define clearly its functional requirements. In the case of SL, it had 144 compared with 3000 for Santiago metro's CBTC project.

"There is no magic number for the number of requirements, but you don't want too few or too many," Mr Klavs Hestbek Lund, operation and maintenance project manager with Metroselskabet in Copenhagen, told me. "The contractor has to know exactly what it is expected to supply, but the more requirements you have the harder it is to check whether the contractor is fulfilling them. It is also important to ensure that your requirements aren't too vague, otherwise you will end up with a lot of extra costs." In any event, everyone needs to be fully briefed on the path chosen, and follow it to the letter.

There was a consensus at the conference that once the contract has been awarded the customer and the supplier need to work as a team to solve problems together for their mutual benefit.

There was also some debate about the need for back-up systems in order to guarantee reliability and availability. Systems such as CBTC by their very nature have a lot of built-in redundancy, and while it is great for manufacturers to sell two train control systems rather one, the operator is faced with additional capital and maintenance costs for a system that may never be used.

But all the latest technology in the world will be for nought if operators fail to pay adequate attention to staff training, both in how to use the new systems and how to get the best out of them for both the railway and its customers.