system
Given the following post, respond as if you're commenting on Reddit:
human
[Lotr] If we have a highway road starting from the Grey Havens and ending at the very end of Mordor, how long does it take to cross Middle-Earth by car?

For example, the road would go between Isengard and Helm's deep, crossing trough the Black gate and next to Mount doom. And we jump in a family car and speeding like 120-30 kilometers/hour. How long would it take to reach from the shores to the end of Mordor?
gpt
Middle Earth is roughly the size of the European continent. If you lay the Gray Havens over Ireland, the Shire would rest over the west country of England. Mordor would reside over Romania and Hungary. It's a rather large territory, so it would cover many countries. "the end of Mordor" could mean many things.

Going from a nebulous center-point of Ireland to Romania is about 2,510 kilometers. Assuming you had the ability to drive at a constant 120 km/h without stopping, turning, or refueling, you'd be able to drive from the Havens to Mordor in 21 hours (give or take).

Any small changes in your course, border laws, and other things will add time to the journey.