As time went on the Alpine passes were improved to make travel easier. A few passes (e.g. the Semmering, the Brenner, the Col de Tende and the Arlberg) had carriage roads constructed before 1800, while those over the Umbrail and the Great St Bernard were not completed till the early years of the 20th century. Most of the carriage roads across the great alpine passes were thus constructed in the first half of the 19th century, largely due to the Napoleon's need for such roads as modes of military transport. As late as 1905, the highest pass over the main chain that had a carriage road was the Great St Bernard (), but three still higher passes over side ridges have roads—the col de l'Iseran, the Stelvio Pass (), the Col du Galibier (), in the Dauphiné Alps, and the Umbrail Pass ().