Glen Koorey presented at the 2013 Transportation Research Board Annual Meeting (Washington DC) on studies investigating whether a suitable maximum traffic volume on local streets could be identified. A residents' survey on four conventional "local" streets with varying traffic volumes in Christchurch found that those living next to higher volumes felt that their streets were busier, noisier, less safe and they tended to have less personal involvement and/or knowledge of their neighbours. An appropriate environmental capacity appeared to be around 1,500-2,000 vehicles/day.
A subsequent study looked at further Christchurch streets with treatments such as street calming and tree plantings, and a higher environmental capacity of around 2,000 vehicles/day was found for the surveyed streets. This suggests that appropriate street treatments can increase the environmental capacity, which has implications for local councils who want to maintain road traffic carrying capabilities without having unsatisfied residents.