The Channel Ports feeding traffic into the Paris-Moskva main line were Hoek van Holland, Vlissingen and Ostend the latter locations being important cross channel ferry points to London. The other major point of departure was Paris.
The Germany-Netherlands and the Germany-Belgium boundary changed little after 1914. The main international routes from Netherlands to Germany crossed that border at three points – Venlo, Arnhem and Bad Bentheim
The main route from Paris to Berlin didn't change significantly after 1945. This was also the route to København and points east of Berlin
Traffic from Paris to northern Germany and beyond often followed a more southerly path as for example Saarbrucken and Frankfurt/Main.