Conventionally traffic junctions have been designed to totally eliminate traffic congestion to the detriment of other road users such as pedestrians. But as society becomes more concerned about the plight of pedestrians, some questions of what is an acceptable congestion are raised. Congestion occurs when the demand for road space exceeds its capacity. This may only be for approximately an hour or so a day or at a particular day of the week: typically on a Friday evening. This may mean that wide roads leading to narrow pavements at a particular place are only needed for a short time during the course of a week. Pedestrians may be inconvenienced for the entire week only to assist drivers for an hour or so per week.