A pedestrian hit by a car travelling at 30km/h has a 10 per cent chance of being killed. If the vehicle is moving at 50km/h the odds of a person dying rise steeply. At the traditional urban speed limit, the odds of a fatal outcome for a pedestrian struck by a car is 80 per cent.
These odds have been advanced as one of the arguments behind a plan to impose a 30km/h speed limit in the Auckland central business district. What is precisely meant by the CBD has yet to be defined by it is generally taken to be the area bound by the
motorways and the harbour edge.
Few of the serious and fatal accidents in Auckland over the last few years have occurred in the CBD. Most have been recorded outside the city's most built-up area, and on arterial roads where traffic moves more rapidly.
Any measure which makes roads safer should be adopted where practical. But what might be effective on the city fringes is not necessarily the right policy
There is clearly a momentum behind the push for a new speed limit in the city. It appears to have firm support within Auckland Council and Auckland Transport though both the Automobile Association and the Auckland Chamber of Commerce argue the city needs what will deliver the best result.
The blanket one-speed-fits-all may not aways be appropriate. AT says average speeds on main roads in the CBD already are below 30km/h. The average undoubtedly reflects the surging number of vehicles using city roads, and especially at peak times when traffic on the exit routes slows to a crawl.
Thousands of cars have been added to the city fleet since the turn of the century and especially in the last five years as the city has grown rapidly off the back of strong immigration. At the same time the population of the CBD has risen as more people have moved into the city, which has added to foot traffic and hence congestion.
Anyone who lives in Auckland knows instinctively that a journey to the city could involve delays. That is partly why public transport patronage has grown and why cyclists, encouraged by a big investment in cycleways, are reappearing.
Together with the cost of downtown parking, and the regional fuel tax — not to mention talk of a congestion charge — barriers to driving a car to the CBD are getting higher. A lower speed could add additional time to that cost.
The CBD low speed zone is due to be released for public consultation in November. AT needs to respond to constructive feedback. It may be that the big city feeder streets — Fanshaw St, Nelson St, Hobson St and Quay St after it heads east past Britomart — are exempt from the 30km/h limit.
At different times of the day traffic moves both smoothly and slowly on these roads, where foot traffic is generally light. Is there a sound rationale for putting the brakes on these routes as part of a blanket policy? If there is, then the public needs to hear it.