Railroad operation in the United States - and, to a degree, in Canada - is dominated by freight. Long heavy freight trains are the order of the day - often running enormous distances (Chicago - Los Angeles, for example).

At the moment there is little passenger operation - but this may change. For a range of reasons, higher-speed passenger service is being studied in a number of places.

Mixing trains with different speed characteristics eats capacity - it's much more efficient, in capacity terms, to have all trains running at a constant speed with a constant stopping pattern. So the proposed super-imposition of more passenger trains running faster has caused warning bells to sound among the freight railroads - who own almost all of the rail infrastructure. Understandably, they want to ensure that they keep their present level of capacity: equally, they do not want to be worse off financially or to have to bear any onerous insurance liabilities.

This has brought to light some differences in standards.

Norfolk Southern will only allow 79 miles/h (127 km/h) on existing freight tracks: higher speeds need a separate right-of-way. Union Pacific is prepared to allow 110 miles/h (177 km/h) on a case-by-case basis. BNSF will allow 90 miles/h (145 km/h) and wants higher speed trains to use a separate track: CSX says the same, but insists on a 30 foot (10 metre) separation between the tracks.

Since these standards are different, are they all correct? Are they all sound? It does sound rather as if someone has put a wet finger in the air, rather than applying science and logic! Maybe someone - perhaps the AAR (American Association of Railroads) with the help of the UIC (International Railway Association) ought to do some kind of risk assessment to see what the parameters are - what are the risks, how can they be managed, and what kind of safeguards are reasonable.

Waht are the risks of mixing high speed passenger and heavy freight? What are the optimal clearances - so that, for example, double-stack container trains can safely work on an electrified railway? What are the insurance needs?

There is plenty of experience around the world of operating freight and high-speed passenger trains on the same infrastructure: let's draw on that to ensure that all possible lessons are learned before we move on to sub-optimal solutions. Those cost money!

Some time ago I posted a blog about the announcements at Farringdon station, served by both London Underground trains and Thameslink trains between Gatwick and Luton airports.

The issue then was that Blackfriars underground station was closed for major reconstruction work and the London Underground station announcers were advising people to use the Circle Line underground stations on either side. However, Thameslink trains run direct to Blackfriars, and would be a much quicker way of getting to where people wanted to go.

Shortly after posting that blog, the announcements changed. Coincidence?

Then, much more recently, I posted a blog about lazy announcements for First Capital Connect's Thameslink services operated by class 377 units. The recorded announcement was to the effect that First Class facilities were at the front and back of the train - ignoring the fact that, if it was an 8-coach train, they were also available in the middle. I made the point that some people might prefer the middle of the train.

Coming home yesterday from St. Pancras, I noticed that the overhead station departure notices took account of this - they said 'First class front, middle and rear'.

Coincidence? Or does someone from First Capital Connect actually read this blog and take notice?

If they do, they can have another challenge.

Some of the seats in the standard class accommodation have armrests which can be raised or lowered. Some of the seats are in groups of 4, so there are two sets of seats back-to-back in places - convenient, because there is luggage space between the seats. However, the armrests can be a nuisance here if they are raised - if passengers are standing (and they do, because these trains have fewer seats than those they are replacing), it is very uncomfortable leaning against two raised arm-rests!