Notes:
Train times are optimal. For some journeys doing the journey in same day requires super early departure and may in fact necessitate an overnight
Time to fly includes arriving at the airport 2 hrs before flight
Train & Plane costs are based on estimates/averages from RyanAir site and https://www.raileurope.com
Flying cost is listed as “Basic” i.e the initial price shown on RyanAir site but there are alwasys extras allowed here at €50
Distances are from Google Maps Travel optins are from Rome2Rio.com
CO2 figures from https://scif.org.uk/web/carbon-calculator/index.html
From the above destinations one must route through Paris or Brussels as indicated There is a direct flight from Rome to Lille but is not very frequent