Research 300 - Speed change management for …

1 Speed change management for New zealand roads Charlton, University of Waikato & TERNZ Ltd Baas, TERNZ Ltd Land Transport New zealand Research Report 300 ISBN 0-478-28712-7 ISSN 1177-0600 2006, Land Transport New zealand PO Box 2840, Waterloo Quay, Wellington, New zealand Telephone 64-4 931 8700; Facsimile 64-4 931 8701 Email: Website: Charlton, ,2, Baas, 2006. Speed change management for New zealand roads. Land Transport New zealand Research Report 300. 144pp. 1 Transport Engineering Research New zealand (TERNZ) Limited, PO Box 97 846, South Auckland Mail Centre, Auckland, New zealand .

2 2 University of Waikato, Hamilton, New zealand . Keywords: New zealand , roads, road hierarchy, self-explaining roads, Speed , Speed change , Speed maintenance, traffic, traffic calming, traffic management An important note for the reader Land Transport New zealand is a crown entity established under the Land Transport management Act 2003. The objective of Land Transport New zealand is to allocate resources and to undertake its functions in a way that contributes to an integrated, safe, responsive and sustainable land transport system. Each year, Land Transport New zealand invests a portion of its funds on Research that contributes to this objective.

3 The Research detailed in this report was commissioned by Land Transport New zealand . While this report is believed to be correct at the time of its preparation, Land Transport New zealand , and its employees and agents involved in its preparation and publication, cannot accept any liability for its contents or for any consequences arising from its use. People using the contents of the document, whether directly or indirectly, should apply and rely on their own skill and judgement. They should not rely on its contents in isolation from other sources of advice and information. If necessary, they should seek appropriate legal or other expert advice in relation to their own circumstances, and to the use of this report.

4 The material contained in this report is the output of Research and should not be construed in any way as policy adopted by Land Transport New zealand but may be used in the formulation of future policy. 5 Contents Executive 7 1. 2. Literature Speed change treatments ..16 Gateway treatments ..16 Physical thresholds ..17 Visual thresholds ..18 Summary of Speed maintenance treatments ..20 road width ..21 Number of lanes ..22 Delineation ..23 Medians ..23 road surface.

5 24 Physical restrictions ..25 Signs ..26 Roadside features ..27 Area-wide urban traffic schemes: a meta-analysis of safety effects ..29 Traffic calming for the prevention of road injuries: systematic review and meta-analysis ..31 The effect of altered road markings on Speed and lateral position: a Summary ..35 3. Sample site Method ..37 Results ..37 Summary ..39 4. Expert Method ..40 Results ..41 Treatments for Speed Treatments for Speed change ..47 Summary.

6 52 5. Findings and 6. 7. 6 Executive summary 7 Executive summary The goal of the present Research , carried out between July 2004 and June 2005, was to identify and develop Research findings that would enable the development of Speed management approaches for New zealand roads akin to self-explaining and sustainably safe initiatives elsewhere. After the project was begun, the National road Safety Committee and the Ministry of Transport articulated a National Speed management Initiative which stated: The emphasis is not just on Speed limit enforcement, it includes perceptual measures that influence the Speed that a driver feels is appropriate for the section of road upon which they are driving in effect the 'self-explaining road .

7 ' To meet the original goal, and provide information consistent with the implementation of the National Speed management Initiative, the project began with an extensive review of published Research in the areas of traffic calming, self-explaining roads, and perceptual countermeasures, which was then summarised in an annotated bibliography. The review of the published literature on Speed management identified two distinct types of Speed management treatments based on different functions: Speed change treatments that clearly indicate a change in Speed , Speed maintenance treatments that encourage drivers to maintain an appropriate Speed in the zone.

8 The Research literature associated with Speed change treatments at village gateways or urban thresholds has shown that their location has important implications for their effectiveness; if they are not accompanied by downstream changes in road conditions such as decreases in road width or increases in urban density, the Speed reductions produced by the gateway may dissipate within 250 m. At other Speed change locations (typically within urban or village areas) visual treatments ( signage & perceptual narrowing) appear to be more appropriate for higher- Speed environments whereas physical treatments producing deflection or discomfort (chicanes, Speed humps, and judder bars) may be unsuitable for speeds higher than 30 50 km/h.

9 A wider range of treatments for Speed maintenance was identified in the Research literature, in part because these designs are intended to reinforce appropriate speeds across a greater range of operating speeds. Some of the most effective treatments have manipulated lane width, the number of traffic lanes, and central medians to moderate vehicle speeds. Roadside features such as the proximity of angle parking and landscaping also have a perceptual narrowing effect and reduce drivers' speeds. Other treatments such as changes in road surface, centre lines, signage, cycle lanes, and footpaths have also been employed, but with lower levels of effectiveness.

10 Physically restrictive measures such as periodic placement of Speed humps and chicanes have been reported to be effective but much less desirable because of their low acceptability to road users and residents. The product of the literature review was: Speed change MANAGEMENTFOR NEW zealand ROADS 8 An annotated bibliography containing written summaries describing the Speed management treatments evaluated, methods of investigation, and the pertinent findings or conclusions of 38 of the key published papers. Summary tables describing the Speed maintenance and Speed change treatments that have been found to be most effective in the literature.