ISOCS' Class 4,5 is going to visit the glass factory at Hergiswill next week. Here's the train timetable page for that journey. I've circled the Ecocalculator in red in the lower left corner of the page.
When you click on the Ecocalculator symbol, more information opens up:
The page tells us that "By making your planned journey by train you will generate 15 times less CO2 and consume the equivalent of 2,5 litres less petrol than if you go by car." The bar charts tell us about the "CO2 (Carbon dioxide), Energy consumption and travel time per journey".
Clicking on two further choices, we can learn more details of energy consumption, and usable time comparison:
For nearly all trips, taking the train will use less energy per traveler, and take more time. When you have a choice, which mode of transportation do you use? What do you do if you don't have a choice?