MTO s Transition to High Speed Profilers for Measuring Pavement Smoothness

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1 MTO s Transition to High Speed Profilers for Measuring Pavement Smoothness Chris Raymond, P.Eng. Head, Bituminous Section Canadian User Producer Group for Asphalt Workshop November 18, 2012 Why Switch to High Speed Inertial Profilers Faster testing and can eliminate the need for additional lane closures Provides improved safety in comparison to California Profilographs Measures International Roughness Index (IRI) which is consistent with network monitoring Consistent with many North American transportation agencies Recommended by the inertial profiler task group, comprised of members from MTO and hot mix industry. The task group was formed in 2007 to investigate this technology. 2 1

2 MTO Specification Acceptance is based on QA testing Data analysis using ProVAL which is an engineering software application used to view and analyze pavement profiles Based on 3 measurements (runs) Profilers must obtain a certificate of compliance on annual basis through participation in a correlation program Pay factor (bonus/full pay/reduction) is calculated for every 100m sublot based on IRI Payment reduction is also applied for bumps (ie localized roughness) TODRF of 0.6 will be applied to localized roughness pay reduction in 2012; followed by 0.8 in 2013 and 1.0 in Implementation Done in collaboration with the industry Since 2008, MTO conducted an annual inertial profiler correlation MTO used high speed profilers in place of California profilographs in 25% of 2010 and 50% of 2011 contracts MTO specified high speed profilers for all the new contracts in 2012 Currently there are 6 high speed inertial profilers in Ontario that are certified to conduct QA/referee testing in 2012 construction season ProVAL workshops were held prior to the start of phased-in implementation and prior to the start of full implementation to allow users a better understanding of the data analysis program Several studies involving side-by-side measurements using both California Profilographs and high speed profilers were conducted to support a fair and transparent transition to high speed profilers. 4 2

3 2011 Smoothness Data PI and IRI % of Sublots in the Following Ranges Type of Smoothness Measurement # of Sublots Bonus Full Pay Price Reduced Rejectable California Profilograph based on QC (24 contracts) One project has 21 rejectable sublots High Speed Inertial Profiler based on QA (20 contracts) One project has 44 rejectable sublots % 49.8% 4.4% 0.6% % 47.9% 6.4% 1.5% Data Scallops and Localized Roughness % of Scallops or Localized Roughness in the following Categories Type of Smoothness Measurement # of Sublots Total Scallops or Localized Roughness Cat 1 (pay adjustment) Cat 2 (larger pay adjustment) Rejectable Scallop or Localized Roughness per Sublot California Profilograph based on QC (27 contracts) One project has 76 scallops Scallops 53.8% 33.2% 13.0% High Speed Inertial Profiler based on QA (22 contracts) Two projects combined have 169 localized roughness Localized Roughness 55.4% 33.6% 11.0%

4 Challenges Limited number of service providers at the start of implementation Development of a data filtering/analysis procedure Profiler auto-triggering mechanism using reflectors in multilane highways Measurement of localized roughness (bumps) Originally based on TxDOT algorithm which is similar to scallops ProVAL software replaced TxDOT algorithm with Smoothness Assurance Module (SAM) in Version 3 SAM better represents vehicle movement MTO had to run extensive data analyses and industry consultation to support transition to SAM 7 Contract Data Analyses Analysis of Localized Roughness using TxDOT vs. SAM Number of Contrac ts ProVAL 2.7 Results 3 Category Model Using TxDOT Algorithm Category 1 + Category 2 Repair ProVAL 3.3 Results 2 Category Model Using Smoothness Assurance Module (SAM) Category 1 Localized Roughness (LR) Assuming SAM Threshold of 2.4 m/km Repair Assuming SAM Threshold of 3.5 m/km # LR Total Penalty ($) # LR # LR Penalty ($) # LR , , NOTE: TxDOT and SAM follow two different concepts. Therefore, they do not necessarily provide the same localized roughness locations. 8 4

5 Going Forward MTO is in discussions with service providers to investigate opportunities to replace reflectors with GPS Contractors are encouraged to use Grinding Module of ProVAL to assist with repair length and limits The MTO in conjunction with industry continues to monitor the successful implementation of high speed profilers and explore opportunities to improve our smoothness specification 9 Thank you! Questions? Chris Raymond, PhD, P. Eng. Head, Bituminous Section Materials Engineering and Research Office Tel: Fax chris.raymond@ontario.ca 5

6 2012 MTO Specification for IRI Average IRI for a sublot from a set of 3 measurements taken by an Inertial Profiler in each sublot (m/km) Payment Factors > to (1.333 x IRI) > to > to (0.4 x IRI) > Rejectable (requires repairs) MTO Specification for Localized Roughness Incidents of Localized Roughness (MRI determined from three sets of measurements taken by an Inertial Profiler, run through ProVAL Version 3.30, m/km) to Payment Adjustment The Contractor shall receive a payment reduction of $3,000 for each incident of localized roughness located in multi-lane freeways, and $2,500 for each incident of localized roughness located in all other highway types. Repairs will be allowed for any incident of localized roughness in this amplitude range. All incidents of localized roughness shall be repaired in this range. TODRF of 0.6 will be applied to localized roughness followed by 0.8 in 2013 and 1.0 in