On p. 15 of Chapter 1, I was reading about the construction of the Blue Bell turnpike and thinking, first of all "What is a turnpike?" (I've heard the term before, even in modern use, but don't understand what distinguishes it from a regular road or highway?), and seconldy "What's this got to do with anything?"

But of course it was very important to the marital fortunes of everyone if it were easier to travel from one area to another. I was thinking of Mr. Darcy's observation in Ch. 9 of P&P "In a country neighbourhood you move in a very confined and unvarying society." Of course, he is used to a great deal more 'movement' and comings and goings in his day to day existence--"What is fifty miles of good road?"

But, I suppose that was a real issue for people looking for marriage prospects. IF there was no one eligible around, and no one came into the neighbourhood, what would you do?

It's treated humourously in Northanger Abbey:

(Catherine) had reached the age of seventeen, without having seen one amiable youth who could call forth her sensibility, without having inspired one real passion, and without having excited even any admiration but what was very moderate and very transient. This was strange indeed! But strange things may be generally accounted for if their cause be fairly searched out. There was not one lord in the neighbourhood; no — not even a baronet. There was not one family among their acquaintance who had reared and supported a boy accidentally found at their door — not one young man whose origin was unknown. Her father had no ward, and the squire of the parish no children.

But when a young lady is to be a heroine, the perverseness of forty surrounding families cannot prevent her. Something must and will happen to throw a hero in her way.

The Dashwood sisters find their future mates first of all by having someone new come to them (Edward) and then by moving themselves and meeting other people.