Lower speeds benefit all urban road users

Wellington City Council would like your views on proposed changes to the city's Speed Limits Bylaw. It's due 7 August.

Julian agreed to put together a CAW submission.

And you can make your own too - here's some info for your submission. Feel free to copy and paste.

Lower speeds benefit all urban road users

Motor vehicle speed is a leading cause of traffic crashes and fatalities in New Zealand. It has been shown that excessive speed was a leading factor contributing to road crashes, accounting for 34% of fatalities in 1996. After two years, anti-speed campaigns resulted in reductions of 14% to 26% in speed related crashes (Graham 1998). So reducing speeds saves lives and road trauma.

In the national road safety strategy Road Safety to 2010, Land Transport NZ reported that New Zealand ranks relatively poorly for road safety compared with other developed countries, with 2.3 road deaths per 10,000 cars in 2001, slightly better than France with 2.9. Road death rates for other European countries including the UK, Norway and Sweden are about half that of New Zealand. New Zealand had 11.8 deaths per 100,000 population compared with 8.9 in Australia and 6.0 in the United Kingdom (LTSA 2003(1)).

The same document notes that in a collision with a car, pedestrian and cyclist fatalities increase rapidly as vehicle speeds increase, such that "death is virtually certain" if the impact occurs at or above 60 km/h, as illustrated in Figure 1. Conversely, if pedestrians or cyclists are hit by motor vehicles travelling at 30 km/h or less, the probability of death is less than 10%.

Figure 1Figure 1: Impact severity (probability of death) versus speed

In New Zealand in 2006, 10% of fatal and serious crash casualties were pedestrians and 5% were cyclists (Land Transport NZ 2007(1)). While 15% of fatal and serious crash casualties in New Zealand in 2006 were pedestrians and cyclists, this figure rises to 27% for Auckland City, 51% for Wellington City and 32% for Christchurch City (Land Transport NZ 2007(2, 3 and 4)).

Cyclist and pedestrian crashes are relatively high in the cities, where most walking and cycling occurs. These data are recorded in Table 1.

Table 1: Fatal and Serious Crash Casualties 2006


Total Fatal & Serious Crash Casualties

Cyclists %Cyclists
New Zealand
 3020  158 5.2%
 309 10.2%
Auckland City
 184 6
Wellington City
 70  14 20.0%
22 31.4%
Christchurch City
 177 23

In comparison, Netherlands is the safest place to cycle streets in the world. Their philosophy is "Cyclists are not dangerous; cars and car drivers are: so car drivers should take the responsibility for avoiding collisions with cyclists. This implies that car drivers are almost always liable when a collision with a bicycle occurs and should adapt their speed when bicycles share the roads with cyclists".

Lowering operating speeds and speed limits on most urban streets will improve safety for all road users (not just cyclists) and encourage more people to cycle. Reducing motor vehicle speeds will have two benefits for pedestrians and cyclists. People struck by motor vehicles at lower speeds will be less likely to be killed or seriously injured, and also the chances of them being struck will be reduced as motorists have more chance to avoid hitting them, when travelling at lower speeds.

Engineering solutions, education and law enforcement should be used to reduce motor vehicle speeds especially around schools, dense residential areas, home zones and in town centres.

All councils have "road classification systems" whereby main roads are classified as arterial roads, less important roads with some traffic-carrying functions (including bus routes) are called collectors (or similar) and the vast majority of roads are classified as "local" roads. On these roads, traffic movement is subservient to the road's role of providing access. On local streets in urban areas, walking, cycling and other neighbourhood uses of the street should be facilitated. Streets take up too much space to be devoted entirely to motor vehicles.

In its guideline for the setting of speed limits, Land Transport NZ observes "the objective of speed limits is to balance the interests of mobility and safety" (LTSA 2003(2)). The rule requires that the limit should be "safe, appropriate and credible for the level of roadside development and the category of road". This rule, nevertheless, makes it hard for councils to reduce speed limits in urban areas below 50 km/h.

The British equivalent system for the setting of speed limits supports implementation of 20 mph (32 km/h) urban speeds (UK DOT):

"Urban roads by their nature are complex, in needing to provide for
safe travel on foot, bicycle and by motorised traffic. Lower speeds
benefit all urban road users and reducing inappropriate speeds is
therefore an important factor in improving urban safety. Also, it is
on urban roads that the majority of casualties occur, including over
90% of pedestrian and pedal cyclists casualties.

20 mph zones are predominantly used in urban areas - both town
centres and residential areas - and in the vicinity of schools. It
is generally recommended that they be imposed over an area
consisting of several roads. The purpose of this type of area wide
traffic management is to create conditions in which drivers
naturally drive at around 20 mph because of the general nature of
the location, or as a result of traffic calming measures being put
in place."

The myth – speeding gets me there faster
The reality is that speeding doesn’t save much time.

A study was undertaken which compared drivers traveling on a 60 km trip. Those who drove aggressively (heavy acceleration and braking) arrived just five minutes ahead of those drivers who drove smoothly and to the conditions.

Not only were the aggressive drivers putting themselves and others at far greater and needless risk for the sake of a mere five minutes. In the above study they used 30% more fuel!
more at http://www.northshorecity.govt.nz/transport_and_roads/Speed/default.html

I believe that:

* The default urban speed limit of 50 km/h is generally too high and
that speed limits should be 30 km/h for town centres and most
urban local streets.
* Traffic calming measures should be introduced to reduce motor
vehicle speeds where necessary.
* Road user education should be implemented with a "share the road"


1. P. Graham. /Research in Road Safety Advertising: The Speed
Campaign/ Road Safety Research Policing Education Conference
Proceedings (November 1998)
2. LTSA 2003(1). /Road Safety to 2010/, New Zealand Road Safety
Strategy, Land Transport Safety Authority (now NZ Transport
Agency), Wellington, NZ.
3. LTSA 2007(1). Road Death Statistics, Land Transport NZ 2007-1.
4. Land Transport NZ 2007(2). Road Safety Issues - Auckland City,
Land Transport NZ, Wellington, NZ.

5. Land Transport NZ 2007(3). Road Safety Issues - Wellington City,
Land Transport NZ, Wellington, NZ.

6. Land Transport NZ 2007-4. Road Safety Issues - Christchurch City,
Land Transport NZ, Wellington, NZ.

7. LTSA 2003(2). Land Transport Rule, /Setting of speed limits/, Land
Transport Safety Authority (now NZ Transport Agency), Wellington,

8. UK DOT. Update of Circular Roads 1/93, /Setting Local Speed
Limits/, UK Department for Transport 2006.*
9. "Dutch have safest cycling streets", 2009,
10. ACC/LTSA 2000 "Down with speed"