How lorries took over cavalry's rapid deployment role

The question of whether tanks replaced cavalry tests a simple model of technological succession. Bayonets had made heavy cavalry's traditional task of breaking an enemy line much more difficult. Tanks took over that breakthrough role and provided armoured fire positions able to advance with other forces. Much cavalry work, especially in the sixty years before World War I, had come to involve dragoons and other rapidly moving infantry. Motor lorries and motorised infantry performed that movement-and-seizure mission more efficiently than horses. A new system could therefore replace cavalry by doing its everyday tactical job, even while tanks inherited the more conspicuous heavy-cavalry role.