Traffic Calming 

Traffic calming slows the speed of motorised traffic and thus reduces the speed differential between vehicles and cyclists and pedestrians - creating a much safer environment for everybody!

Read about the traffic calming experience in Munich (courtesy of Via Stada's Axel Wilke Velocity 2007 report):

When Germany introduced legislation in the mid 1980s that allowed cities to drop urban speed limits to 30 km/h, Munich started the process of introducing those zones in 1988. The conversion has by now finished, and of the 2,300 km of urban road network, 80% are now covered in 333 individual 30 km/h speed limit zones. The remaining 20% represent the main road network, where the default speed limit is 50 km/h. New subdivisions are automatically built with a 30 km/h speed limit.

Munich's ultimate cycle network is 1,400 km long, of which 1,200 km have been built already. 38% of the existing network is within 30 km/h zones. When streets are reconstructed and the speed limit reduced, it is Munich's policy to remove existing cycle paths or cycle lanes (if these are present), as mixed traffic is by far the safest form of travel for cyclists. The person responsible at the city for the implementation of the cycle network used the following words: "The best and safest cycle path is, ultimately, the one that is not needed because of the traffic structure and the traffic proficiency of the road users."

It's possible to do the same thing in New Zealand, it helps to strengthen communities, improved retailing and has strong support amongst residents, eg the Pt Chev SALT survey of residents.

It's legally possible, see the enabling regulation legislated in 2003: http://www.landtransport.govt.nz/rules/setting-of-speed-limits-2003.html  Section 3.2(5) of the rule allows local councils freedom to set appropriate speed limits, eg 30km/h in residential, retail and employment neighbourhoods.

A 1980's banner from the Dutch cycling advocates' campaign: "50 is too fast!"