Road safety to 2010

Appendix 2: Improving the road environment

This strategy’s mixed approach to road safety includes improving the road environment.

This appendix looks in more depth at New Zealand’s road network and the types of safety engineering initiatives that can reduce road trauma. Specific activities are outlined in the 2003 Implementation Schedule included with this strategy.

Road safety engineering must be tailored to the road environment. In this strategy, we distinguish between five road environments, each with different types of crashes and demanding a different mix of engineering treatment.

Length
New Zealand has just over 90,000 km of public roads. The bulk of the network (72 percent, or around 65,000 km) consists of minor open roads. Most of the rest is made up of state highways (11 percent) and minor urban roads (14 percent). Major urban roads make up 2.6 percent and motorways 0.4 percent.

Traffic volume
New Zealand’s roads carry about 37 billion vehicle kilometres of traffic every year (‘vehicle kilometres travelled’ is the sum of kilometres travelled by all motor vehicles in each year. It is a measure of mobility and thus also exposure to risk.) State highways and major urban roads each carry
about 30 percent of this traffic, minor open roads 15 percent, minor urban roads 14 percent and motorways 10 percent.

Social cost
The social cost of a crash is the measure of all costs that the crash inflicts on the community — on road users, emergency service providers and others. It includes not just the costs of material losses (such as medical treatment and property damage) but also pain and suffering.

Crashes on the road network cost the community about $3 billion every year. State highways account for more than 42 percent of this, minor open roads for 24 percent, major urban roads for 19 percent, and minor urban roads and motorways make up the remaining 15 percent.

Risk
Risk is defined as the social cost per vehicle kilometre travelled. Roads with high risk do not necessarily produce a high level of road trauma because traffic
may be very light, but they do expose individual users to a greater danger of injury.

State highways and minor open roads are the most risky roads for crashes involving motor vehicles. For each kilometre travelled on these roads, there is a 50 percent higher chance of crashing than on the network as a whole, and three times more than on motorways. Major and minor urban roads are about half as risky as state highways and minor open roads.

Cost density
Cost density is defined as the social cost per kilometre of road. Roads with high cost density do not necessarily expose individual users to a greater danger of injury, but they do produce a high level of road trauma because there is more traffic.

Cost density is about 10 times higher on motorways and 10 times higher on major urban roads than over the network as a whole. This means that every kilometre of these roads produces on average 10 times as much social cost as the network as a whole.

Summary statistics (PDF 430KB).

Transit New Zealand safety projects over $3 million

Within the 2010 strategy’s timeframe, approximately 20 percent of the predicted total benefits of the capital works budget will be safety related. This includes trhe following projects over $3million, and an additional 120 projects below that level.

Project name	Earliest start date	Construction cost ($000)

SH1 Longswamp to Rangiriri	03/04	$6,500
SH2 Mangatawhiri deviation	04/05	$23,000
SH1 Normanby realignment	03/04	$6,600
SH2 Domain Road intersection	03/04	$4,200
SH1 Tumai — Waikouaiti realignment	04/05	$4,300
SH5 Tapapa curves realignment	03/04	$7,600
SH2 Rimutaka corner easing (Muldoon‘s)	06/07	$4,700
SH3 Mangaone Hill four laning	04/05	$3,500
SH1 Katetoke/Oakleigh Streets intersection	04/05	$3,500
SH1 Hihitahi Bluffs realignment	04/05	$12,400
SH2 Maramarua deviation	07/08	$15,000

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Page created: 17 October 2003