The problems with running overnight services are:
- the cost (several locomotives, paths, the Trenhotel services were generously supported by the Spanish government)
- difficulty in obtaining paths as infrastructure managers want overnight possessions / conflicts with evening and night freight
- inherent lack of comfort in running an overnight service (compared to daytime services)
- delays (e.g. formalities and locomotive changes at borders)
- age of rolling stock (France has pledged to invest in some new rolling stock for its overnight services) and in particular comfort of sleepers
- limited capacity of sleepers means they are expensive
- lack of showers at stations
- arrival times not early enough for working day or too early for comfort (only small window of what is attractive)
- lack of a common European booking system - night trains are often part of a longer journey
If there is no serious investment in night services they will continue to decline, at least in the short term. The German CityNightLine has been more successful that many night services, perhaps because of the use of portion working and reforming of the train overnight for most of its services, allowing more destinations to be served. I would suggest that to reinvigorate these services, air travel also needs to be more heavily taxed. Greater co-operation and more creative thought on the part of the operators and infrastructure managers could also be part of the solution. The Paris - Italy services could perhaps be restructured along the following lines, if there was a greater willingness to do so:
Train 1 - Paris (17.45) - Dijon (20.15) - Lyon (22.15) (via Modane, Torino) - Genova (04.30 - admit that this is not attractive) - Pisa (06.30), portion for Firenze (07.30)/ portion for Roma (09.00)
Train 2 - Paris (20.30) - Dijon (23.00) - (via Modane) - Torino (06:00) - Milano (07:30) - Verona (09:00) - Venezia (10:45 - not so important for working day), connection Milano - Bologna for arrival around 09:00, connection to Roma with arrival around 11:00 for those who want later departure from Paris.
Train 1 - Roma (19.45) / Firenze (21.15) - Pisa (22.15) - Genova (00.15) (via Torino, Modane) - Lyon (06.30) - Dijon (08.30) - Paris (11.00)
Train 2 - Venezia (18.45) - Verona (20.30) - Milano (22.00) - Torino (23.30) - (via Modane) - Dijon (06.30) - Paris (09.00), connection Bologna - Milano with departure around 20.30, Roma - Milano with departure around 18.00 for arrival in Paris at start of working day.
This would attract significant new markets (Lyon, France's second city, Torino, Pisa, possibly Genova). Through ticketing SNCF/Trenitalia/Eurostar/Thalys + overnight service with fares significantly lower than those of the two individual legs combined with hugely help the business case.