Arterial and Bridge Needs Assessment (ABNA) Pavement Rating Crosswalk Methodology
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Arterial and Bridge Needs Assessment (ABNA) Pavement Rating Crosswalk Methodology October 14, 2019 Background Maricopa Association of Governments (MAG) is in the process of developing an interactive tool to inform future decision making and project investment. As part of the tool development process, the consultant team has collected pavement performance data from Maricopa Association of Government (MAG)’s Member Agencies. Because the data is collected in various formats depending on the region (See Table 1), it needs to be translated to one consistent measure in order to develop consistent shapefiles of each region’s pavement condition. The purpose of the following memo is to provide documentation of the crosswalk with methodology for transforming all Member Agency data. Table 1: Member Agency Pavement Ratings Rating System / Approach Agency PCI Apache Junction, Avondale, Fountain Hills, Gilbert, Glendale, Goodyear, Maricopa, Mesa, Paradise Valley, Peoria, Phoenix, Queen Creek, SRPMIC, Scottsdale, Tempe Pavement Quality Index (PQI) Chandler Overall Condition Index (OCI) Surprise, Wickenburg Pavement Surface Evaluation and Rating (PASER) El Mirage, Buckeye Excellent (5) to Failed (1) Guadalupe, Litchfield Park, Florence PCR Maricopa County Page 1 of 7 The following table provides definitions of the rating systems used based on interviews with the member agencies and outside research. Crosswalks were developed based on these definitions. Table 2: Pavement Index Definitions Rating System / Definition Rating Approach PCI PCI is typically measured using a visual survey in 0-100 accordance with ASTM D6433 or ASTM D5340. Pavement Quality City surveys pavement, such as the smoothness of 0-100 Index (PQI) roadways and any signs of distress in the pavement surface. Overall Condition The Overall Condition Index is an average of several 0-100 Index (OCI) measures including; the depth of rutting, smoothness of the surface, and cracking of the asphalt or concrete roadway.1 Pavement Surface The PASER pavement rating process assigns a 0-10 Evaluation and Rating condition rating based on distress patterns and road (PASER) condition descriptions according to the PASER manual.2 Excellent (5) to Failed This rating system includes the date the arterial 1-5 (1) segment was sealed and maintenance schedules. Pavement Condition PCR is measured by deducting the value of cumulative 0-100 Rating (PCR) distresses based on visual surveys.3 Crosswalk Methodology Because the Pavement Condition Index (PCI) is the most predominant evaluation measure,4 all condition data will be translated into a Pavement Condition Index score. PCI is a combined numerical rating on a 0- 100 scale representing the severity and extent of a wide range of pavement distress types for a designated section of road.5 PCI is typically measured using a visual survey in accordance with ASTM D6433 or ASTM D5340. To compare PCI, PASER, and Pavement Condition Rating (PCR), the team referred to Ram et al.’s Developing a Correlation between the Pavement Condition Ratings used by Five Federal Lands Management Agencies, written for FHWA and published in 2016. This article utilized data for around 1 UDOT. Project OCI. 2015. https://www.arcgis.com/home/item.html?id=4f34e74cdc314fdeb97297826856a604 2 Ram et al., 2016. 3 MCDOT State of the System Report. (2017). https://www.maricopa.gov/DocumentCenter/View/318/State-of-the- System-Report-PDF 4 Ram et al. Developing a Correlation Between the Pavement Condition Ratings Used by Five Federal Lands Management Agencies. (2016). Transportation Research Record Journal of the Transportation Research Board. 5 ASTM D6433 methodology. 2019. Page 2 of 7 300,000 miles of federal public roads that utilized various performance rating scales and compared them. PQI PQI is a measurement determined by surveys of roadway smoothness and distress signs.6 The rating is represented on a 0 to 100 scale. Both Chandler and Tempe use PQI. Since both PCI and PQI measure similar components through similar means, the team determined that PQI and PCI ratings can be considered equivalent. Table 3: PQI Condition and Scores PQI Score Excellent 85-100 Good 70-84 Fair 55-69 Poor 40-54 Very Poor 25-39 Serious 10-24 Failed 0-9 OCI The team used the following equation to determine OCI’s relationship to PCI.7 = (0.80 ) + (0.20 ) Because Surprise is the only city using OCI, and they also provide Roughness scores, (equating to IRI in the formula above) scores, we are able to use this equation. 6 Ibid. 7 Binnie, Diane et al. PCI/IRI/PCR: Formulas to Combine to Rate an Urban Street Network. (2016). 2016 ESRI User Conference. Page 3 of 7 PASER The PASER pavement rating process assigns a condition rating based on distress patterns and road condition descriptions according to the PASER manual.8 Both El Mirage and Buckeye utilize PASER. Ram et al. provide the following crosswalk from PASER to PCI with a high confidence level for correlation. Figure 1: PASER to PCI Crosswalk PASER PCI 10 – Excellent 100 9 – Excellent 89 to 99 8 – Very Good 78 to 88 7 – Good 67 to 77 6 – Good 56 to 66 5 – Fair 45 to 55 4 – Fair 34 to 44 3 – Poor 23 to 33 2 – Very Poor 12 to 22 1 – Failed 0 to 11 1-5 Rating One entity, Guadalupe, used a 1-5 scale, representing 5 as excellent and 1 as failed. Because the PASER data is represented on a 1-10 scale, the team equated this system to the PASER system used by Ram et al. The team translated PASER’S 1-10 scale into a 1-5 scale by dividing by 2. Table 4: PASER Crosswalk to PCI 1-5 Rating Scale PCI 5 – Excellent 100 4.5 – Excellent 89 to 99 4 – Very Good 78 to 88 3.5 – Good 67 to 77 3 – Good 56 to 66 2.5 – Fair 45 to 55 2– Fair 34 to 44 1.5 – Poor 23 to 33 1 – Very Poor 12 to 22 .5 – Failed 0 to 11 8 Ram et al., 2016. Page 4 of 7 PCR: The Pavement Condition Rating is a 0-100 scale computed using detailed pavement distress and pavement smoothness data collected using an automated data collection van. is Ram et al. provide “Simplified,” “Detailed,” and “HPMA-Predicted” ratings method for PCR and PCI comparisons. The team chose to use the “Simplified” ratings method for this crosswalk methodology for ease of translating the PCI rating to additional condition measurement types. The proposed crosswalk for comparing PCR and PCI is presented as follows. Ram et al. provide a high confidence level for this comparison. In the accompanying “Example Pavement Calculations” document, a conversion is provided for PCR to PCI to prorate the values for each side. Figure 2: PCR to PCI Crosswalk PCR PCI 96-100 – 100 Excellent 86-95 – Good 88 to 99 61-85 – Fair 54 to 87 0-60 – Poor 0 to 53 Next Steps: Defining Good, Fair, and Poor Once all ratings are translated to PCI rankings, the team will use the below table to simplify these ratings into Good, Fair, or Poor ratings. To simplify PCI rankings into good, fair, and poor, the team developed the following crosswalk. Table 5: Good/Fair/Poor crosswalk to PCI PCI PCI Rating Good/Fair/Poor Equivalent 86-100 Excellent Good 71-85 Good Good 56-70 Fair Fair 41-55 Poor Poor 25-40 Very Poor Poor 11 - 25 Serious Poor 0-10 Failed Poor Page 5 of 7 “Poor” scores equate to a PCI score below 55, falling into Very Poor, Serious, or Failed categories. “Fair” scores are comprised of the Poor and Fair categories, between 56 and 70. “Good” scores were provided to scores of 71 through 100, falling into the PCI categories Good and Excellent. This simplified rating system will be added to area shapefiles to visualize pavement condition by road segment. Page 6 of 7 Figure 3: Overview of Pavement Classification Crosswalk *Graphic excludes OCI Legend Excellent Very Good Good Fair Poor Serious Failed Page 7 of 7 .