The replies have been brilliant thanks!
Can anyone shed a light on why Paris metro system has Goa1 for 3b,7b and 10 yet is operating at Goa4 for the others mentioned ?
3b, 7b and 10 are short lines which see less traffic than the other lines. Running semi or fully automatic would be quite expensive and gain little.
Can anyone highlight other European countries that operate on Goa1 ?
Amsterdam, Rotterdam, Berlin, Antwerp, Brussels.
What about the rest of the world for Goa2 and Gao3?
To name a few:
GoA 2: Vienna, Glasgow, Brussels (in the future)
GoA 3: Budapest, Barcelona
Its interesting to see the polarizing views on Goa4...…some countries embracing the technology whilst other countries seem reluctant. What's peoples views on this do you believe it depends on the culture of the country, the politics or is it a cost/deliverability issue ?
Again thank you for the great replies
In a greenfield situation, such as when the Copenhagen Metro started, it's relatively easy to roll out GoA 4. As you're building a completely new metro system in a city which hasn't had one before, there is no legacy infrastructure to deal with (think: trains, existing tunnels, platforms already built, technology already operational). Furthermore, there will be no unions or staff protesting over potential job losses. This makes rolling out something completely new relatively easy.
While there might be some armchair critics who are afraid of trusting computers with a safety-critical job, these are usually a minority and their voices will go silent once the system has been operational for a while.
In a brownfield situation (existing metro, staffed, existing rolling stock) you will have to get the unions on board (after all, GoA 4 means no more drivers), you will have to adapt platforms and rolling stock, you might have to upgrade the signalling system, and so on. At the same time, the metro line has to remain operational as the traveling public depends on it. Unless there are serious capacity gains from going to full unattended operation, in many cases it's simply not worth the hassle. In that case, rolling out GoA 2 will also increase capacity (see Thameslink) while being less disruptive.