1、Standard Practice for Collecting the Transverse Pavement Profile AASHTO Designation: R 88-181 Technical Section: 5a, Pavement Measurement Release: Group 1 (April) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-5a
2、R 88-1 AASHTO Standard Practice for Collecting the Transverse Pavement Profile AASHTO Designation: R 88-181Technical Section: 5a, Pavement Measurement Release: Group 1 (April 2017) 1. SCOPE 1.1. This practice outlines a method for collecting pavement transverse profile, including its relationship to
3、 a level horizontal reference in pavement surfaces utilizing automated measurement devices. The profile can subsequently be used to quantify cross slope and pavement distresses such as transverse deformation, rut characteristics, water entrapment, or edge drop-off. Detailed specifications are not in
4、cluded for equipment or instruments used to make the measurements. Equipment that can be adequately validated to meet the functionality stipulated herein is considered acceptable. The goal is to achieve a standardized data set that supports a wide variety of interpretation methods to characterize pa
5、vement transverse profile characteristics in order to capture properties of engineering significance, without unduly restricting innovative methods. 1.2. This standard addresses data collection utilizing a measurement device traveling at or near the posted speed limit. 1.3. This practice does not pu
6、rport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations related to and prior to its use. 2. TERMINOLOGY 2.1. Defi
7、nitions: 2.1.1. report intervalthe travel distance between the reported data. 2.1.2. transverse profilevertical deviations of the pavement surface from a level horizontal reference perpendicular to the lane direction of travel. 2.1.3. transverse measurement widthdistance between the first and last m
8、easurement points in the transverse profile. 2.1.4. vertical measurement resolutionthe smallest distance of measurement in the vertical axis stored by the measure device. 2.1.5. vertical measurement accuracythe difference between the vertical distance reported by the measuring device and a standard
9、reference measurement. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-5a R 88-2 AASHTO 3. SIGNIFICANCE AND USE 3.1. This standard provides guidelines for collecting transverse pavement profile for t
10、he subsequent extraction of selected pavement characteristics such as rut, cross slope, deformation, and edge drop-off. 3.2. Two data reporting intervals are to be selected based on the level of detail required in the subsequent analysis. The longer interval is typical of network data collection, wh
11、ile the shorter is more often related to project-level data acquisition. 4. DATA COLLECTION 4.1. General GuidelinesEach agency shall designate the lane(s) and direction(s) of travel to be surveyed or rated based on sound engineering principles and management needs within the agency. The following gu
12、idelines are recommended as minimums to provide a necessary database and for long-term uniformity. 4.2. The report interval between collected transverse profiles should not exceed 3.0 m (10 ft) for network-level collection and 0.5 m (1.5 ft) for project-level collection. 4.3. For network-level colle
13、ction, at least one direction should be surveyed on undivided roads and both directions on divided highways. On undivided roads, measurements on the side carrying the heaviest truck loads are desired, when this knowledge is available in advance of the survey. 4.4. It is desirable to survey the same
14、direction of travel and the same lane during subsequent survey cycles. 4.5. The transverse profile shall have a minimum width of 4.0 m (13 ft) for detecting distresses in the lane (between the longitudinal lane markings, when present) and 4.25 m (14 ft) if interpretation of edge drop-off is desired.
15、 The extra width should be on the shoulder side of the lane, beyond the edge marking. These widths include 300 mm (12 in.) beyond the normal requirements to account for vehicle wander. Data measured outside the location of interest may be discarded before reporting if a lane identification algorithm
16、 is employed at the collection stage. Note 1The technology for high resolution transverse profile data collection is advancing rapidly. Currently, the most widely deployed technology involves mid-angle optical methods that are subject to providing false or no data due to the nature of the surface. H
17、ighly reflective surfaces such as rail tracks, manholes, steel patch plates, or ponding water cause measurement difficulty. Different pavement surface types also require the camera to adjust, which can take several potential profiles to recover. These issues typically involve a limited portion of th
18、e pavement and can be dropped without a significant impact on the values required for pavement management. A right-of-way camera image can be of significant value when resolving issues of this type. Newer, high-angle optical techniques may significantly reduce the occurrence of these problems. 5. DA
19、TA REQUIREMENTS 5.1. The transverse profile shall have data points with separation of less than or equal to 10 mm (0.4 in.). 5.2. Vertical measurement resolution shall be less than or equal to 1 mm (0.04 in.). 5.3. Vertical measurement accuracy shall be less than or equal to: 2018 by the American As
20、sociation of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-5a R 88-3 AASHTO 5.3.1. 3 mm (0.12 in.) when the average elevation of that same profile is used as a reference; 5 mm (0.20 in.) when an absolute-level horizontal elevation is
21、 applied as a reference. 5.4. The profile shall be measured along a transverse line that deviates less than 15 degrees perpendicular to the lane centerline. 6. SYSTEM VALIDATION 6.1. The process of calibrating and checking the performance of the measurement equipment is the responsibility of the age
22、ncy. Agencies should evaluate and confirm the manufacturers recommendations for calibrating and verifying the performance of the equipment relative to their intended data use. 6.2. Measurement System Elements to Be ValidatedThe following elements of the measurement system should be validated: 6.2.1.
23、 Distance measuring instrument accuracy. 6.2.2. Data point spacing. 6.2.3. Transverse measurement width. 6.2.4. Vertical measurement resolution and accuracy relative to the vehicle. 6.2.5. Vertical measurement accuracy relative to a level horizontal reference. 6.2.6. Effect of operational and enviro
24、nmental variables, including: 6.2.6.1. Sun angle, intensities, shadows, temperature, and precipitation on the pavement surface; and 6.2.6.2. Measurement speed variability. 6.2.7. Pavement cross slope, vertical grade, roughness, and horizontal curvature. 6.3. Validation reference for certification is
25、 manual measurements of surveyed lane sections made by trained technicians on suitable test sections designated by the agency. Multiple 3-m (10-ft) long test sample interval sections should be employed. One manual reference transverse profile measurement is performed in each test sample interval. Th
26、e manual transverse measurement interval should not exceed 25 mm (1 in.). The test sample sections should be as uniform as possible along their length to reduce differences in exact measurement location. The longitudinal measurement interval of the manual reference transverse profiles should not be
27、more than 150 mm (6 in.). Artificially manufactured artifacts with known dimensions, such as steel plates or wires, placed through the length of the test sections, may be used to assess system resolution and accuracy. All validation reference values must be measured to a true level reference. The va
28、riability in the reference measurement process needs to be assessed. When possible, at least three repeat manual reference transverse profile measurements should be performed on at least three test sections. 6.4. Validation/Acceptance Report: 6.4.1. The validation reference report will include asses
29、sments from multiple transverse elevation profiles. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-5a R 88-4 AASHTO 6.4.2. The acceptance report should tabulate the data from at least five equipment
30、 runs and the validation reference values. It should also include: 6.4.2.1. The results from the resolution tests performed in at least four locations across the pavement. 6.4.2.2. The effects of operational and environmental variables investigated in the validation. 6.5. The operator and driver are
31、 critical components of the total measurement system. They must be trained in equipment operation including instrument failure detection and system management. Smooth, precise operation of the instrument platform is necessary for optimum results. 6.6. The formal validation and performance measuremen
32、ts should be supplemented with a routine operational check program in which the equipment measures a standard set of test sections on a regular basis. The check sites should be representative of the pavement system being measured. Time series analyses are used to check for changes in the measurement
33、 system not caused by changes in the road being measured. A typical implementation of this system check process would involve monthly measurements on a defined set of sections where the agency has knowledge of maintenance, construction, or other activities that could change the transverse profile of
34、 the test sections. 7. KEYWORDS 7.1. Automated pavement data collection; pavement cross slope; pavement distress; pavement edge drop-off; pavement evaluation; pavement management; pavement monitoring; pavement surface; pavement transverse profile; rut; rutting. 8. REFERENCES 8.1. AASHTO R 87, Determ
35、ining Pavement Deformation Parameters and Cross Slope from Collected Transverse Profiles. 8.2. ASTM E1656/E1656M, Standard Guide for Classification of Automated Pavement Condition Survey Equipment. 8.3. FHWA. Distress Identification Manual for the Long-Term Pavement Performance Program, FHWA Report RD-03-031. 1Formerly AASHTO Provisional Standard PP 70. First published as a full standard in 2018. 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.
