What part of Europe?

And what do you mean by "reasonable large town"?

Italy was the Country of A Thousand Cities and they were (and still are) arranged along Roman routes and waterways.

A good example is the Via Aemilia that runs from Piacenza to Rimini (and from those starting points actually connecting Milan to Rome through other roads) cutting the Po plain.

Via Aemilia's route is still used today and the major italian autoroute runs parallel to it for its northern trait, still connecting the principal cities of North Italy.

The Po plain is a large alluvial plain with regular and abundant water sources, fertile land and more or less an uniform distibution of resources. It was then ideal to the Roman agricultural and surveyong system, that survived far into modern times (and, again, is still visible).

This preamble to say that, in this ideal landscape, there are large/town cities at "one legion day of march" from each other, or 25 kilometers, almost to the meter. Those larger centers have smaller ones beteween them. You can check by going to google maps and creating a route from Milan to Bologna, no autoroute. Google will bring you along SS9, aka Via Aemilia, and you will meet Piacenza, Parma, Reggio Emilia, Modena, Bologna, in this order, each one at 20/30 km from the previous one. Between them smaller towns, one ore two if the cities are longer away: places like Fiorenzuola, Fidenza, Sant'Ilario, Rubiera, Castelfranco, Faenza and so on. Major centers like Milan, Bologna, Florence, are about 200 km apart

This was the North Italian ideal situation: every 15 kilometers or so you could find a plave to rest or a small marketplace.

On horse you can reasonably expect to ride 25 kilometers in 4 hours, and a riding day was considered about 8 hours.

By foot, a trained walker can easily cover the 25 kilometers from major town to major town inside a walking day, with a nice resting stop at the intermediate town.

An ox cart isn't really faster than walking, so a farmer from a villa or a small town could expect to bring their produces to market leaving at town, spend the day selling, spend the night on their cart or in an hostel, and be back in the next morning.

So, if you wanted to go, say, from Modena (reasonably big town) to Bologna (next city), you can have breakfast at home leave with yourlunch packed and dine with your friend in the city.

Add a day for each successive town, so if you are from Reggio, you have a two day walk in front of you: better send a note to your friend in Modena: you are spending the night there. You can shave half a day if you are an excellent walker or you travel by night (I advice against it).

If you have an horse you could even go from Modena to Bologna, pop a visit, and go back that night. Is a bit of a stretch but if you are in a hurry...

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The northern plain ad Via Aemilia is an ideal situation. Most of Italy is mountains, and the major cities are on the coast, so you can expect to miss those nice towns along the road, and the nice road itself.

Times can thus vary, but to a lesser extent that you can expect: while major cities can be farther away (deducing from the transhumance time: add three days if you have to cross the Appennines from sea to sea, and bring an armed excort) Italy truly is the Country of a Thousand cities, and cities need travel, so you could expect to find an irregular circle of towns in a 25/35 km (one day walk) radius from every major city, with several villages and villas in between, a major town every 50/75 km (two days) and a big city every 200 km (four, five days).

This is an IDEAL urbanistic distribution, and Italy, even outside the Po Plain is a fairly ideal place as urbanization is concerned. Other places could have longer stretches of forest, mountain ranges and even deserts: travelling through Switzerland or Spain wouldn't have been the same.

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Four centuries later... the situation is pretty much the same. No major city founded, just the old ones growing, and a person still walks at the same speed, as horses do. The first major change in personal travelling speed will come with the train.

Sources:

Enrico Guidoni, Arte e Urbanistica in Toscana (1000-1315); Bulzoni, 2016

Enrico Guidoni, Angelica Zolla, Progetti Per una Città. Bologna nei secoli XIII e XIV; Bonsignori, 2018