The research, carried out during 2002, has examined the effect of Variable Mandatory Speed Signs (VMSS) on road user behaviour within the Ngauranga Active Traffic Management Scheme (NATMS), just north of Wellington, New Zealand. The VMSS show speed limits which are considered appropriate during normal (incident free) conditions and reduced speed limits in response to an incident.
Speed data was acquired through the use of automatic incident detection (AID) cameras using video imaging processing (VIP).
The VMSS are located within the NATMS and are just one component of the dedicated ATMS architecture provided to deal with incidents aimed at reducing delay to road users. The speeds indicated by the VMSS are mandatory and are the only example of such features in New Zealand.
Normal speed data and speeds during incidents were recorded over the period January to August 2002.
Keywords: diversionary effect, incident conditions, normal conditions, peak time, speed, speed constraints, speed change, speed variability, variable mandatory speed, weather conditions