TYROSAFE Tyre and Road Surface Optimisation for Skid Resistance and Further Effects Karen Scharnigg BASt (Federal Highway Research Institute) 3rd International Road Surface Friction Conference Safer Road Surfaces – Saving Lives 15th – 18th May 2011, Gold Coast (Australia)

Project information FP7 Coordination Action Consortium: AIT, former: arsenal research (Austria) BASt (Germany), IFSTTAR, former: LCPC (France), RWS-DVS (The Netherlands), TRL (UK), ZAG (Slovenia), FEHRL (Belgium) Duration: 2 years (July 2008 – June 2010) Webpage:

(safety) (energy) (health) Background Skid resistance Rolling resistance Noise emission © different … - measuring policies - measuring methods - measured parameters Interdependencies ??

Objectives / Concept raise awareness, coordinate and prepare for European harmonisation and optimisation of the assessment and management of essential tyre/road interaction parameters to increase road safety and support greening of European road transport

WP6 Management WP1 Policies of EU countries of skid resistance, rolling resistance and noise emissions WP2 Harmonisation of skid- resistance test methods and choice of reference surfaces WP3 Road surface properties – skid resistance, rolling resistance, noise emissions WP4 Environmental effects and impact of climatic change – skid resistance, rolling resistance, noise emissions WP5 Dissemination and raising awareness future influence Work Packages

WP1: Policies of EU countries of skid resistance, rolling resistance and noise emissions Topics Review of...  EU policies and standardisation work  Current position in EU member states  Differences, advantages/disadvantages of approaches Recommendations for future harmonised policies Pictures provided by CEN/TC227/WG5 and AIT

WP1: Policies of EU countries of skid resistance, rolling resistance and noise emissions...current status (concerning skid resistance): skid resistance - considered as an important surface property no formal EU policy has been issued yet policies only on national level Policies exist in many European countries … with different focus on different networks (... more and higher level policies for high-level roads...) with different machines or underlying standards with different “depth” “Everybody is doing it, but everybody is doing it differently.”

WP1: Policies of EU countries of skid resistance, rolling resistance and noise emissions...recommendation for future harmonised policies – skid resistance: apply to Level 1 and Level 2 networks (motorways and principal roads linking major towns) apply to in-service roads (not to new asphalt surfacings) - the network should be monitored every year; maximum: every 3 years, in both directions measurement technique - Continuous measurement using a device for which there is an established standard (e.g. a CEN TS) values averaged over not more than100 m for comparison with thresholds Threshold levels will be based on the risk of skidding on different types of site with the overall objective of equalising skidding accident risk across the network. …

Topics: Test methods and reference surfaces for skid resistance in EU member states Differences, advantages/disadvantages of harmonization approaches Suggest a harmonization method (reference device and surfaces) Road map/implementation plan (2010, 2015, 2020) WP2: Harmonisation of skid-resistance test methods and choice of reference surfaces

23 different devices for measuring skid resistance identified – devices mostly used: pendulum, SCRIM/SKM, GripTester measuring principles: Longitudinal (LFC) and sideways (SFC) friction coefficients slip ratios varying from ABS to locked wheel different test tyres different operating conditions  Some projects on skid resistance measurement harmonization were executed, but... no common scale or harmonized method available yet

18/06/2009Drafted by P G Roe, suggestions by MT Do Spec. for new device Conversions developed Measurement standard written QA/calibration Procedures established New machine developed Existing single machine chosen as reference Existing device type identified as reference Ref. fleet identified HARMONISED EU SYSTEM Reference group principles chosen C B D1 D2 COMMON SCALE OPTIONAL USE COMMON SCALE A Determination of the common scaleEU application E national transition to common scale FULL EU STANDARDISATION national transition to standard scale Replace national fleets with standard device C Common Scale harmonising by reference to average of a group of machines of a single device type. B Common Scale harmonising by reference to the average of a group of machines from different device types but of similar operating principle. A Common Scale harmonising by reference to the average of all device types in use that have a defined technical specification. Common Scale using one specified machine as the reference device. D LineDescription Optional use of common Scale for comparisons where a linked national device is available. E All national fleets evolved to reference device Road Map

Topics: describe different parameters of road surfaces and tyres identify interdependencies recommendations for optimisation of road surfaces and tyres identify lack of knowledge and proposals for further research concerning the optimisation of road surfaces and tyres WP3: Road surface properties – skid resistance / rolling resistance / noise emissions

Problems – optimising surface properties Problems: currently surfaces and tyres – optimised separately  various aims for optimising, but similar focus (e.g. road - high skid resistance; tyre – wet friction)  different parameters for optimising  surfaces tested with specified methods – surfaces are optimised according to the test methods  tyres tested on specified surfaces – especially according to ISO surfaces and tyres – optimised mostly with regard to one of the three surface properties

DIFFERENT IMPACTS can be influenced can‘t be influenced can be partly influenced Surface parameters vs. road surface properties

Interdependency matrix – surface parameters (excerpt) parameters (asphalt surfaces)SRRRNE aggregate properties shape  +/o?+ angularity  +-o polishing resistance  +?o mixture parameters max aggregate size  +++ binder content  +/-? void content  +/-+- laying & compacting chipping material – aggregate size  +++ chipping material – polishing resistance  +?o degree of compaction  ??- finished surface layer thickness  ??+ absorption  oo+ shape factor  ??+... still knowledge gaps  research needs

Future research – research areas identified thirteen main research areas  most important - how to measuring and interpreting texture as well as the contact patch of a tyre on the surface with regard to the three surface properties  divided in surface parameters (including measuring systems and environmental parameters), tyre parameters (including measuring systems and environmental parameters) and surface/tyre interaction - simulation models cover a period of about 20 years

WP4: Environmental effects and impact of climatic change Topics: Environmental implications of optimising skid resistance  Establish the importance of the various factors involved  Establish current state of knowledge Identify areas for future research on environmental effects Consider potential impact of climate change

WP4: Environmental effects and impact of climatic change Strand 1: The influence that providing harmonised/optimised skid resistance could have on the environment Strand 2: The effect of climate change on skid resistance Increased use of polish resistant aggregates (effects of quarrying and production, emissions from transportation, increased tyre wear  particle emissions, increased rolling resistance  fuel consumption and GHG and other exhaust emissions, reduced maintenance?) Increased texture depth (increase in noise) Likely scenarios for temperature, rainfall patterns, etc How skidding risk may change How to address these changes – material specifications (texture depth, drainage,...) Impact on harmonised/optimised skid resistance (Including measurement techniques/survey strategies, will surface characteristics change over time (In different ways? Or on different timescales?)) Following points were discussed:

Webpage – public part (Documents – public) presentations of the Workshops deliverables other publications

Thank you for your attention and interest on behalf of the TYROSAFE team!