Road protests in the United Kingdom usually occur as a reaction to a stated intention by the empowered authorities to build a new road, or to modify an existing road. Some of the reasons for opposition to opening new roads include: a desire to reduce air pollution and thus not wishing to incentivise increased or sustained car usage, and/or a desire to reduce or maintain low noise pollution by not having or increasing the use of motor vehicles in the area of the planned/proposed road. Protests may also be made by those wishing to see new roads built or improvements made to existing roads. Motivations for protests may be altruistic or selfish. In some cases, protests have also acted as a training ground for individuals and groups who continue to be active in campaigning and advocacy.