I found a similar but not quite perfect question/answer at:
Possible distance travelled by horse over 6 weeks?
The thread was great, I learned about palfreys and relays, etc. My scenario is a little different. Not a single horse/rider scenario, but a team and carriage. My best guess is that a team of two horses pulling a carriage with four people might travel ~ a few miles per hour. Perhaps 3 - 5 miles per hour. So, for two hours travel time, around 8 miles would be traversed.
Is this right?
Very much depends on road, kind of carriage, total distance to cover and who's chasing you.
In Roman times, with relatively good roads, average daily distance was between 40km and 60km.
Distance between caravansarais, on the Silk Road, were about 40km apart.
Conestoga wagons on the Oregon trail traveled 15-20 Mi (24-32 Km).
Chose Your pick.
In July 1821, my great great grandmother travelled 36 miles on the Monday and this included a stop at Grantham to vist St Wulfram's Church and have lunch and then 48 miles the next day which included a tour of Lincoln Cathedral and having lunch. She travelled, as I understand it, in a carriage with 2 horses and a coachman. There were a total of three people in the coach. So not 20 miles a day but proably nearer 60 as one doesn't tour Lincoln Cathedral in 10 minutes so I expect they spent a couple of hours in Lincoln. They had travelled from Leadenham in the morning (13 miles),then travelled to Glanford Brigg after lunch (25 miles) and then on to Great Limber for the night (10 miles). I may know more when I finish transcribing her diary. She hasn't yet described her mode of travel but in 1820 she says in her reminiscences: "Another time all over North Wales. This was in 1820. We went in Mr. S's carriage with 2 horses and a coachman who did not like it at all. There were no Turnpike roads except where the Mails went to Holyhead and the Welsh roads were very bad. One day we went from Barmouth to the Harlech - so steep and rough a road that the horses could hardly accomplish it. My sister said she dare not go back, so the coachman took the horses back to Barmouth and a driver came with three pretty little Welsh ponies, to whom he talked all the way, and they brought us safely back."
Assuming good quality roads without significant elevation changes, healthy horses and well maintained carriage:
These based upon accounts such as the one by Mr Richard Everard in this thread, London cab records, etc.
Hansom cab horses did about 18 miles per day, indefinitely, moving rather quickly but in relatively short bursts.
Stagecoaches covered up to 60-70 miles per day (more usually half this), but they changed horses frequently, each team only doing 15 miles per day. They also went faster, averaging 5-8mph.
And in detail answer to your question: In ONE hour a 2-horse, 4-person carriage could travel about 15-20 miles. At which point they would then stop, and dispose of the dead horses.
In 1858, John Butterfield of the Butterfield Overland Stage Co.and his New York associates made a contract with the Post Office Department that made possible the first semiweekly mail service to and from California. When Butterfield guaranteed to deliver the mail between St. Louis and San Francisco in 25 days or less, he was awarded a $600,000 annual Post Office subsidy. As in the case of so many transportation developments in America—land, sea, and air—carrying the mail was the decisive factor. Passenger freight, even at full capacity, would not defray operating expenses over Butterfield’s 2,800 mile route. 112 miles a day.
