In nearly every historical book set in the Regency, we find characters traveling by coach from one destination to the next. The question is: How expensive was it to do so?

The Hyde Park Gate in London, erected by the Kensington Turnpike Trust. This was the first toll point encountered along the Bath Road, upon leaving London. ~ Public Domain ~ https://en.wikipedia.org/wiki/
Turnpike_trusts#/media/
File:Hyde_park_turnpike_toll_
gate.jpg
First, the major roads during the Regency were TOLL ROADS. Readers should keep in mind that the person hiring or owning the carriage paid the toll. Many aristocrats trusted a footman with the task of actually paying the toll keeper, but it was the responsibility of the person letting or owning the carriage to see that the fee was paid. Turnpikes had been established with toll gates and tolls set by local parishes, who were responsible for maintenance of their stretch of road. Rates were variable, as were the distances between toll gates–could be anything from 10 miles apart to 30 miles apart. [I live in North Carolina. Our tolls are often determined my the number of cars using those lanes.]
Jane Austen’s World provides us this description of A View of London: Tottenham Court Road, 1812. “Inquiring readers, I had read about the closeness of rural areas near London during Jane Austen’s day. This image of Tottenham Court Road from the 1812 edition of Ackermann’s Repository shows the countryside beyond the toll gate. One imagines that Jane Austen was accustomed to such vistas when she visited her brother Henry in London. One moment she would be traveling through the countryside, the next moment she would be entering a teeming metropolis (Click here to see map):
“In the first years of the eighteenth century, pastures and open meadows began by Bloomsbury Square and Queens Square; the buildings of Lincoln’s Inn, Leicester Square and Covent Garden were surrounded by fields, while acres of pasture and meadow still survived in the northern and eastern suburbs outside the walls. Wigmore Row and Henrietta Street led directly into fields, while Brick Lane stopped abruptly in meadows.“World’s End” beside Stepney Green was a thoroughly rural spot, while Hyde Park was essentially part of the open countryside pressing upon the western areas of the city. Camden Town was well-known for its “rural lanes, hedgeside roads and lovely fields”where Londoners sought “quietude and fresh air.” – Extract from “LONDON The Biography”, by Peter Ackroyd. Published by Vintage, 2001.
Or, perhaps, you might find an earlier piece of mine entitled, The Beginning of the Turnpike Roads in Georgian England, helpful.
Next, we must consider how much time was involved in the journey. I often research the distance from point A to B in current miles, and then I make appropriate adjustments for time of year of the story, proximity to the London Road or other major roads, etc., before I add the travel to the story. More than once, I have had to make major adjustments to my “time” profile of the story before I could finish writing it. Time for the journey depends on several things: weather (time of year), how much money do the characters have available (more money means more ability to hire horses, and the character can hire a team instead of a pair), and quality of the horses and carriage.
The stage and mail coaches generally took 2 days or about 20 to 30 hours of travel, depending on the coach and specific route taken. There were a couple of route options on the Great North Road. For a post chaise, the cost was about 1s 6d a mile for a pair of horses, and double that for four. So it was not really an economical method of travel. Tickets on the stage or the mail coach were cheaper, but travel was slower. (It is claimed that the highwayman Dick Turpin rode from London to York in less than 15 hours on his mare Black Bess. No idea if such was actually true, but a horseman can get over bad ground far easier and faster than wheels.) A trick I learned from another writer was to use Google Maps and set up one’s search for “traveling by bicycle” to estimate traveling by carriage during the Regency era.
Snow and mud slows everything down. An author does not even need to write in a broken axle, just bad weather. Even rain that takes out bridges or flooded rivers that must be forded will put a stop to travel.
In estimating the speed of the travel, one must consider a number of factors. As mentioned above, the journey would be much slower in mud because horses can pull a tendon or a shoe in mucky ground. One must figure the average speed of a walk = 4 mph, trot – 4-12 mph, and that was the safest gait at which to travel. It is symmetric, meaning the horse is less likely to slip. We see movie images of stage coaches with horses cantering and galloping, but the post chaises–the fastest conveyances in Regency England–only averaged 11 mph, and that was in summer, when the roads were best. A galloping horse can do 35 mph, but not for long, especially not when hauling a load.
An excellent source to consult is Following the Great North Road Then and Now: A Guide for the Modern Traveller, by Louise Allen. “From the Romans to the present day the Great North Road has carried travellers between London and Edinburgh. Roman emperors, Samuel Pepys, Dick Turpin and Jane Austen are only a few of famous and infamous travellers who passed along this iconic route. Despite bypasses, dual carriageways and concrete, the old road remains to be explored, and this guide is for any curious traveller who wants to break the monotony of a long drive by discovering the picturesque towns and curious byways on this route through British history. With it you can travel in the wheel tracks of coach passengers in the early 19th century, before the railway and the motorcar changed travel for ever.” The book describes the old road as it would have been in the coaching days, shows where the modern road diverges from it, lists a number of the inns along the way, and some description of the scenery as it would have been and various landmarks along the way.
A private light weight vehicle could go about 7 to 8 miles an hour for short distances on decent roads. “16 mile an hour tits” meant carriage horses could do 16 miles an hour. This would be a good, fit, well fed team. The trick was it was impossible to sustain this pace for miles and miles and miles. If one was going for speed, he would change horses every 10 miles, which is about once an hour.
In Jane Austen’s Pride and Prejudice, Mr. Darcy tells Elizabeth Bennet that fifty miles of good road was “little more than half a day’s journey.” And the roads were so good to Brighton that they were often used for setting speed records.
Much of the above information can be found at https://shannondonnelly.com/2009/06/14/horse-sense/

Poster advertising the letting of tolls, 1826.
Unknown – National Library of Wales ~ Public Domain ~ https://en.wikipedia.org/wiki/Turnpike_trusts#/media/
File:To_Be_Let_The_Tolls_Cribbin,_
Llanfihangel_and_
Pencader_Gates_1826.jpg
As to costs at an inn, those also varied, depending on the type of inn (is it a high class one or not) and services required. The American Joseph Ballard wrote in 1815: “Besides the fare in the coach you have to pay the coachman one shilling per stage of about thirty miles, and the same to the guard whose business it is to take care of the luggage, &c. &c. You must pay also, at the inns, the chambermaid sixpence a night, the “boots” (the person who cleans them) two pence a day, and the head waiter one shilling a day. The porter who takes your portmanteau up stairs moves his hat with ‘pray remember the porter, Sir.’ In fact, it is necessary in travelling through England to have your pocket well lined with pounds, shillings and sixpences, otherwise you never can satisfy the innumerable demands made upon a traveller by landlord, waiters, chambermaids, and coachmen, &c. &c. My bill at Manchester for one supper, a dinner, a breakfast, and two nights lodging was five dollars. (About a pound).”
So…cost for inns were pretty expensive. A night on the road not so bad….several days due to whatever problems could quickly mount up.
Other Resources:
Thoughts on Travel in ‘Sense and Sensibility’

The Hyde Park Gate in London, erected by the Kensington Turnpike Trust. This was the first toll point encountered along the Bath Road, upon leaving London. ~ Public Domain ~ https://en.wikipedia.org/wiki/
Turnpike_trusts#/media/
File:Hyde_park_turnpike_toll_
gate.jpg
This is very useful. Thank you, Regina.
Glad you liked it, Lillian.