11111111111111111111111111111111111111111111111111111111111111111111111111111111 • 3 1010 00066993 9 SPEED ZONE IDENTIFICATION TRIAL VIC ROADS PRINCIPAL TRAFFIC ENGINEER'S DEPARTMENT QUALITY AND TECHNICAL RESOURCES DIVISION GR 92-5 1992 , "- - ~- - ~ ..... - - '_'-. -" .., :._. __ r' - • 1_ ......,"., \ ......... ". stack 082 VR/GB 92-5 Copy 5 SPEED ZONE IDENTIFICATION TRIAL GR 92-5 082 VR/GR 92-5 Copy 5 Uber, Charles B. Speed zone identification S·tack 36407 VIC ROADS PRINCIPAL TRAFFIC ENGINEER'S DEPARTMENT QUALITY AND TECHNICAL RESOURCES DIVISION VIC ROADS KEW Vic 3101 1992 ISBN 0 7306 1351 8 Available from VIC ROADS Bookshop 60 Denmark Street KEW VIC 3101 Phone (03) 854 2782 Fax (03) 853 0084 VIC ROADS REPORT DOCUMENTATION PAGE Report No. Report Date: ISBN Pages GR 92-5 December 1992 07306 1351 8 41 Title and Sub-title: Speed Zone Identification Trial Author(s) Type of Report & Period Covered: Dr. Charles Uber General Report : Februazy 1991-April 1992 Performing Organization(s) • Sponsoring Organisation. Principal Traffic Engineer's Department VIC ROADS Quality and Technical Resources Division VIC ROADS 89 High Street Kew Victoria 3101 AUSTRAliA Executive Group/Steering Committee: Working Group/Study Team: E.V. Barton, Principal Traffic Engineer Charles Uber, Tim Strickland Abstract: Continued suggestions from the public resulted in VIC ROADS syndicate trial of means of increasing driver awareness that they had entered a reduced speed zone. This report documents a subsequent, more extensive trial of rumble alerting strips, pavement numerals and yellow versus white longitudinal lining (edge, lane and centre lines) as individual and combined devices to increase driver awareness of the change in speed zoning. The results show the a total "WHITE ZONE' treatment is more effective than the total 'YELLOW ZONE' treatment. Pavement numerals had a mjnjmal value in reducing vehicle speeds. Rumble alerting strips of 12 mm height were effective in reducing vehicle speeds at distances of 200 to 700 metres after the start of the reduced speed zone, however, the reduction of speeds is not considered sufficient to justify widespread installation. Key Words: (IRRD except where*) Disclaimer: Speed Limit, Rumble Strip, This report is disseminated in the interest of Speed, "'Pavement Marking information exchange. The views expressed are those of the authors, not necessarily those of VIC ROADS. Reproduction of Form and completed page is authorised. EXECUTIVE SUMMARY Members of the public repeatedly have suggested a need for increased signing of speed zones on roads or the use of coloured lines to show the speed limit within a speed zone. In 1988 a VIC ROADS syndicate trialled 'YELLOW ZONE' treatments of yellow transverse speed bars, yellow pavement numerals and yellow centre line with yellow raised reflective pavement markers. Some effects on slowing vehicle speeds were noted but needed more rigorous statistical analysis. Further trials with improved painting and with thicker speed bars were suggested. This current study at three trial sites and three control sites investigated treatments of white versus coloured longitudinal lines (centre, lane and edge), pavement numerals and rumble alerting strips. These treatments are studied separately and in different combinations. Trial and control sites on the two lane, two way Princes Highway West approaches to the City of Colac had a 100 km/h speed limit reducing to a 2. a km long 75 km/h intermediate speed zone and further reducing to the 60 km/h built-up area speed zone. The west approach had the 'YELLOW ZONE' treatment. Trial and control sites on the two lane divided carriageway Bellarine Highway approaches to Leopold had a 100 km/h speed limit reducing to a 0.6 km long 75 km/h buffer (transition) speed zone before a relatively short 60 km/h speed zone. The west approach had rumble alerting strips placed prior to white pavement numerals. A trial site at Tarrawingee with a control site at Everton were both on west approaches on the two lane, two way Ovens Highway. The 100 km/h speed limit reduced to an 80 km/h hamlet speed zone before returning to the 100 km/h speed limit. At Tarrawingee white pavement numerals were placed prior to placing rumble alerting strips. Rumble alerting strips of about 12 mm height, placed in a group of three about 70 metres in advance of the start of a hamlet or transition speed zone caused reductions of mean speeds from 1.9 to 3.2 km/h at distances of 200 to 700 metres after the start of the speed zone as compared to similar control sites. Pavement numerals at the start of a reduced speed zone did not provide consistent results, but the effect does appear to be minimal. This is true whether the pavement numerals are used separately or in conjunction with rumble alerting strips. Reductions of both mean and 85%ile speeds were greater in a 'WHITE ZONE' than in the 'YELLOW ZONE'. None of the reductions in speeds in the reduced speed zones were considered to be of sufficient magnitude to justify the adoption of any of the treatments for normal use. However, rumble alerting strips or pavement numerals may be useful to alert drivers of their approach to some problem sites. CONTENTS Page 1. INTRODUCTION • . 1 2. STUDY OBJECTIVE 1 3. BACKGROUND ••. • . 2 3.1 Australian Standard 2 3.2 Australian Practice 2 3.3 VIC ROADS syndicate 2 4. TRIAL • • • . • . • . 4 4.1 Trial site Locations 4 4.2 Rumble strips 6 4.3 Data Collection 6 4.4 Evaluation 8 4.5 Cost of Treatments 8 5. RESULTS OF THE TRIAL ••••••.••.••.• 9 5.1 Effect of Rumble strips Alone 9 5.2 Effect of Rumble Strips After Pavement Marking Numeral 13 5.3 Summary of Effect of Rumble strips_ 14 5.4 Effect of Pavement Marking Numeral Alone 16 5.5 Effect of Pavement Numeral After Rumble strips 16 5.6 Summary of Effect of Pavement Numerals 16 5.7 Total Effect of 'White Zone' 17 5.8 Total Effect of 'Yellow Zone' 18 5.9 Comparison of 'White Zone' and 'Yellow Zone' Effects 18 5.10 Long Term Effects 18 6. DISCUSSION 20 7. CONCLUSION 21 REFERENCES . 22 APPENDIX A: Site Layouts . • . 23 APPENDIX B: Photographs ......... 30 APPENDIX C: Calculations of Significance . 37 1. INTRODOCTION It is difficult to conceive of any road traffic issue that generates as much heated reaction from the public and with as little knowledge as the issue of speed limits and their enforcement as a necessary part of the road safety package. The use of speed cameras in Victoria since 1990 has greatly enhanced the ability of police to enforce speed limits. In view of this, there is a greater obligation on road authorities to ensure that speed limits are set at the appropriate value and properly signed and otherwise identified to improve the motorist's awareness of the applicable limit. To this end, A VIC ROADS syndicate (1988) developed and trialled a "YELLOW ZONE" concept to improve the identification of a 80 km/h speed zone as a buffer between the 100 km/h open rural highway speed and the 60 km/h built-up area speed zone. The concept included:- - yellow coloured centre line markings; - numerals painted on the road at the start of the speed zone; transverse bars marked across the pavement or depressions in the pavement just in advance of the speed limit sign; - yellow raised reflective pavement markers (RRPM's) instead of white on the centre line; - the normal speed zone signing was provided including repeater signs at regular intervals; - larger signs. A general evaluation of this tended to suggest that these measures would be effective in encouraging drivers to stay under the speed limit. The report of the Social Development Committee of the Parliament of victoria 'Inquiry into speed limits in Victoria' (1991) included recommendations - 3. VIC ROADS investigate methods of educating road users about the reasons for speed zoning. 21. Present signing techniques be continued. Submissions from several rural councils were in favour of the use of coloured linemarking to differentiate speed zones, use of pavement numerals and use of painted stripes or bands across the road. 2. STUDY OBJECTIVE The objectives of the Speed Zone Identification Trial are to more formally study the effect of white or coloured (yellow) centre line markings, the effect of pavement marking numerals at the start of a speed zone, and the effect of audible or tactile rumble strips on driver compliance with the speed limit. This report presents the results of the evaluation of trials incorporating the different measures. - 2 - 3. BACKGROUND 3.1 Australian standard Australian Standard AS 1742.2-1986 includes in Section 4. Pavement Markings and Devices a sub-section quoted below. 4.2.7 Colours. colour of pavement markings shall be white, except for the alternative uses of yellow specified below. Yellow may be used in place of white in the following cases: (a) Unbroken portion of barrier lines. (b) parking lines to indicate areas whose use is restricted. Black may be used in the gaps of a broken pavement line to heighten contrast where a light coloured pavement does not allow adequate line definition to be obtained. This does not establish black as a standard colour. Where yellow is used, the colour shall be Golden Yellow, Colour No 356 in AS 2700 (see Clause 4.6.3 for the colour of RPMs and RRPMs). 3.2 Australian Practice The Department of Main Roads in New South Wales had used yellow centrelines for years, but has ended the practice. In Victoria, yellow coloured linemarkings are used in the Melbourne metropolitan area to mark the tram 'Fairway' system. This involves the use of broken or unbroken yellow lines marking tram clearance.