Defining what a street was became more complicated from the seventeenth century on. The process of differentiation was at work on the highway as it was in so many other aspects of life. The entry of more and more vehicles pushed other traffic to the margins. Pedestrians retained their right of access to every part of this carriageway but received, by way of compensation for the effective loss of the centre, exclusive use of the footways which were raised up from the vehicle level and given a special surface. These different spaces developed distinctive rules and procedures. On the passageway for wheel and hoof, for example, tradition and then law kept users to the left, while on the part reserved for foot passengers anarchy prevailed, moderated slightly by a vague sense that keeping to the right was preferable. In the competition for space, the carriageway tended to have the advantage, although pedestrian interests began to receive the support of by-laws by the 1840s in their efforts to resist the erosion of their sovereignty.