What was it like to travel during the middle ages?

Before I try and answer, I should say that the vast majority of what I know about travel in the 14th century is specific to England, so what I present here may not be totally applicable to other regions. Now, on to the question...

As in any era, how, why, and where people traveled in the middle ages was hugely influenced by a person's status and wealth. For the majority of the population, mostly agricultural workers tied by feudal law to the land they worked, regular travel did exist but it would mostly take the form of walking into the nearest market town to buy and sell and then walking home. In England, by the mid 14th century, almost all towns and villages were less than 10-15 miles apart, making even the most remote farmer's trip into town less than 8 miles, an easy day's trip to and from by foot. Because towns were so close together, even a person traveling by foot at a rate of 10-20 miles a day would be able to find accommodation each night, whether that be at an inn or, hopefully, someone's home (Inns where usually expensive and innkeepers often wouldn't let just anyone stay).

As for the actual traveling, maintaining infrastructure wasn't typically high on a manorial lord's to-do-list. Roads were very often uneven, muddy paths carved out through repeated travel rather than purpose built roads. Many Old Roman roads were still intact and would have been in somewhat better condition, but these were less common. Bridges too were likely to be poorly maintained if they were present at all. Many roads might have simply stopped at the bank of a river and continued on the other side, forcing travelers to wade or ford across.

Roads weren't safe either. Outlaws and, to a lesser extent, wild wolves or boars were known dangers. Travelers stopping for the night might seek out others heading in the same direction the next day and move as a group to deter bandits. Arming oneself was also standard.

Travel times, of course, depended on the means of travel. Moving alone, a healthy adult might cover 10-20 miles per day by foot and 20-30 miles per day by horse. Wagons and coaches were uncommon means of transport during the 14th century even among nobility and typically covered 10-15 miles per day.

Considering the uncertainty of over-land travel, it's unsurprising that, whenever practical, trade goods would be moved via rivers.

Traveling by sea was, of course, necessary but often cramped, unpredictable, and unpleasant. Storms and bad weather could easily send a ship off course or sink it altogether and pirates were also a very real danger.

The two most common seafaring vessels in 14th century England where Hulks and Cogs, both clinker-built sailing ships. The distance these ships could travel per day depended greatly on the whether and wind direction. In good weather, such vessels might travel 40-70 miles per day.

One final factor of travel in Medieval times to take into account was the lack of maps. Though they existed, they were almost never intended for use by travelers, instead typically being drawn on large sheets of stiff velum and mounted on walls as a sort of status symbol showing off the owner's knowledge of the world. While naval travelers could use compasses, lunar tables, and astrolabes, those traveling over land would have to rely on knowledge of the terrain and basic sun-and-star navigation. If traveling in an unfamiliar land, one might hire a guide or else have to rely on the spoken directions of locals.

I hope this information helps. If you're interested in learning more about travel in 14th century England, I'd recommend checking out 'The Time Traveler's Guide to Medieval England' by Ian Mortimer: http://www.amazon.com/Time-Travelers-Guide-Medieval-England/dp/1439112908