With Green Wave, one or more roads can be closed completely to vehicles in case of terror, disasters, VIP escorts or large sporting events. In that way, a dangerous situation can be minimised by closing an area. With the technology created by SaCS, traffic lights can react within a few seconds. Thus, authorities are able to divert traffic in the desired direction, either via predefined patterns or patterns created as a result of individual decisions made according to the situation. This could be done by a PDA which is wirelessly connected to the SaCS server. With the PDA, the user is able to control the traffic lights and thereby traffic itself.