Category Archives: Walking

Development Contributions (DC) higher density traffic bonus

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Looking at the statement in the Outline of significant changes to the Development Contribution Policy 2018/19 – Page 5

“Under the existing policy some high-density developments received a discount for placing lesser demand on the Council’s services – but in fact placed demand equivalent to those of larger dwellings”

Note the key word change here is “high-density” in the proposed DC policy reports, whereas it was “higher density” in previous DC policy. When it comes to traffic in Hamilton, increasing (higher) density cannot be said to place equivalent demands on roading infrastructure as lower density areas. The graph below shows the wider Nawton area population trend line increasing at a steeper angle than the local traffic trends line.

What is being suggested in the new DC policy is that the location of a suburban stand-alone 3-bedroom dwelling on a 650m2 section places an equivalent demand on services as a 3-bedroom dwelling in a higher-density urban area. This is where the definition of “high-density” may be clouding assumptions. It is possible that high-density (such as High Rise) has greater costs than suburban density, but urban density is debatable.

The traditional traffic assumption is that a new suburban “3-bedroom dwelling equals 10 traffic movements per day”. The proposed 2018 DC policy (p42) for 2-bedroom and 1-bedroom dwellings uses “Residential Conversion Factors – Two Bedroom – Factor = 0.689 & One Bedroom – Factor = 0.477” (p41), which rounds up to 7 and 5 traffic movements per day respectively.

This next graph measures, as percentages, the wider Hamilton East area population growth vs traffic actual vs traffic predicted.

The above graph includes the actual and predicted Ruakura/Peachgrove intersection counts. We should note that the development of Hilda Ross retirement village occurred around 2002, quickly followed by Ruakura/Peachgrove/Wairere road building. Once the construction work force left this area, traffic movements evaporated to a level below that in 2002, despite the 200-plus dwellings having been built at Hilda Ross village for about 450 people (census mesh block 0896002 & 0896402). Yet at its gate is an oversized road designed to cater for predicted phantom trips (see below for predicted traffic), which by design has a negative/deadly impact on safety for weaker road users in the area.

To Summarise: the wider Hamilton east area’s density increased from around 1,900 people per km2 (ppkm2) in 2001 to 2,200 ppkm2 in 2013. For Hilda Ross village, which is dominated by smaller dwellings, there is a population density of over 5,000 ppkm2. However, a negative effect on traffic movements appears to be measureable. Like the assumptions used to predict the 80,000 vpd for 2026, the 0.477 factor for 1 bedroom homes is an assumption, not a fact.

For more on one-bedroom dwellings, Hamilton City Library has Kol Peterson’s book Backdoor Revolution: The Definitive Guide to [Accessory Dwelling Unit] ADU Development

The following excerpt is from Chapter 9: Impacts on a City

“Space efficiency and location efficiency – In general … neighbourhoods that are walk-able, bike-able, or transit oriented … Residents in such neighbourhoods will tend to have dramatically fewer vehicle miles travelled in a year than US residents living elsewhere.”

Reference: Ruakura Peachgrove Noise AECOM Nov 2009 – page 84 – Table 9: Predicted 2026 Upgraded Traffic Volumes

 

Grey St too be 75% safer

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Over the past 7 years no less than seven people have died travelling to/from/within the Hamilton CBD.
Grey St, Hamilton East has recorded ZERO fatalities.

Better than that, the people from the Hamilton East Community Trust teamed up with HCC, NZTA and WRC to be one of six case studies around Australia and New Zealand being assessed by a team of Austroads traffic safety experts.
The outcome of the team work-shop was that safety improvements were identified that could easily halve the risk of serious injury to people visiting and moving through central Grey St.

Key safety improvements included treatments that helped to manage vehicle speeds, such as raised platforms, gateway treatments, road narrowing, textured surfacing and additional measures.

In fact the Hamilton East team clearly are looking for transformational change – they have a tick for every box.

The ticking of every box is the right thing to do; this allows different treatments to act together to give the greatest overall benefit.
Here are concept drawings showing how different treatments could give a reduction in the risk of fatality or serious injury of up to 75% for many road users.

Lastly page 14 of the Technical Report tells us we can do better than 75% safer:
“Typically this requires speeds below 30 km/h to avoid death if a collision occurs, or even lower speeds (around 20 km/h) to avoid serious injury. For a speed choice of 30 km/h instead of 50 km/h, the estimated reduction in fatal crash risk is 95%”

But this would be a political decision as it was in Helsinki in the 1990s. “The optimal speed limit on an urban street is the lowest limit the political decision makers can accept”

Link to report – Safe System infrastructure on mixed use arterials