The two main driving forces of the revolutions of 1848 were the liberal middle classes and the urban working classes. Both of these groups' existence can in a way be traced back to industrialization.
The middle classes, to some extent, came about because of industrialization. These were the people who were the managers of factories or stores. They were the clerks who kept records in the businesses and for the government. They came to exist in much larger numbers because of the industrialization of Europe. The working class, of course, came to exist because industrialization pulled them off farms and into the cities to work in factories.
In the early 1840s, economic slowdowns hit Europe (again, a function of industrialization). When this (and other problems) occurred, the classes that we have mentioned started to push for more freedom and democracy.