Manjriker Gunaratne - Academia.edu (original) (raw)
Papers by Manjriker Gunaratne
Digital image based automated pavement crack evaluation has been replacing the conventional manua... more Digital image based automated pavement crack evaluation has been replacing the conventional manual surveys due to its improved efficiency and safety. One popular principle employed in software used for automated detection of cracks from pavement images is based on identifying the intensity contrast between the images of the crack and the rest of the pavement surface. However, it has been observed that this technique results in other non-structural pavement surface irregularities being also detected as cracks, particularly in pavements with Open Graded Friction Courses (OGFC). This issue has a major impact on the accuracy of automated distress evaluation and hence software developers have constantly attempted to address this. Furthermore, since pavement management decisions are based on the crack evaluation results, the overestimation of cracks caused by detection of surface irregularities as cracks could cause improper prioritization of pavements and inefficient utilization of rehab...
The primary findings of this research can be highlighted as follows. Models that provide estimate... more The primary findings of this research can be highlighted as follows. Models that provide estimates ofwet weather speed reduction, as well as analytical and empirical methods for the prediction of hydroplaning speeds of trailers and heavy trucks, were gathered and verified in a field study. The investigators have been able to provide Florida Dept. of Transportation (FDOT) with a predictive tool that combines the best of the available prediction models. Pavement properties needed to estimate the water film thickness produced during sheet flow were obtained from the literature and field studies. The investigators have been able to formulate analytical equations for predicting the critical water film thickness with respect to hydroplaning under different road geometric conditions, such as straight runs, super-elevations, and transition sections. A wet weather crash analysis was performed using crash statistics, geometrical data, pavement condition data, and other relevant information available in numerous FDOT databases. The results of this effort indicate that (i) wider sections are more likely to produce hydroplaning crashes, (ii) dense-graded pavements are more likely to induce conditions conducive to hydroplaning than open-graded ones, (iii) NCHRP's PAVDRN software would have predicted, to a significant degree of accuracy, most of the documented hydroplaning incidents, and (iv) the PAVDRN program is relatively unreliable for predicting hydroplaning in the inner lanes.
Geotechnical and Geological Engineering, 1997
Dynamic replacement (DR) is a relatively new ground-modification technique that has been used suc... more Dynamic replacement (DR) is a relatively new ground-modification technique that has been used successfully to stabilize organic soil deposits by replacing the organic soil with sand columns. A full-scale DR field study was conducted in order to assess its effectiveness on Florida organic soils. A computer-based quality control system was developed using data-acquisition-management techniques to evaluate the degree of improvement
Published in 2006 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boc... more Published in 2006 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2006 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group No claim to original US Government works Printed in ...
Energy and Environment Research, 2015
International Journal for Numerical and Analytical Methods in Geomechanics, 1996
ABSTRACT Analytical determination of stresses and deformations caused by moving loads is vital to... more ABSTRACT Analytical determination of stresses and deformations caused by moving loads is vital to foundation and pavement designs. In current applications, moving loads are often approximated to be vertical impact loads. In this work, however, a live load is modelled as a uniform distribution of normal or shear stresses in actual motion. Then, a layer stiffness approach utilizing linear elasticity is followed in determining the surface and interior deformations due to the live load. By superimposing the two solutions for normal and shear surface stresses, the new approach can be made to provide an approximate solution to the problem of evaluating stresses and deformations caused by a wide wheel load rolling on a layered elastic system. Although elastic solutions in general are inadequate to explain the more significant consequences of pore pressure generation and dissipation in the soil subgrade, these results can certainly be useful to examine the shearing effects of wide rolling wheels on the asphalt layer and immediate settlement of the subgrade. It is found that the dynamic effects of a smoothly rolling wide load are significant at relatively low wheel velocities compared to those of shear waves in the subgrade and base.
Civil Engineering and Environmental Systems, 2011
The hazard potential of Sri Lanka's landslide-prone areas has bee... more The hazard potential of Sri Lanka's landslide-prone areas has been evaluated based on a well-defined decision process involving primary and secondary attributes. The relative contribution (weights) of both types of attributes and the severity ratings of secondary attributes have been defined subjectively on the same linguistic severity scale (‘very high’ to ‘very low’) based on expert judgement and past statistics,
Journal of Transportation Engineering, Sep 3, 2011
Modeling of the pavement image formation process using reflection properties of macrotexture show... more Modeling of the pavement image formation process using reflection properties of macrotexture showed that digital images of concrete pavements can be used to monitor pavement wear. The specific optical characteristics of images and the optimum camera settings that can be used for this purpose were determined by theoretically formulating the Bidirectional Reflection Distribution Function (BRDF) of surface texture with uniform color. In the analytical phase of the study, desired levels of pavement texture were generated by combining a series of 3-D sine surfaces of varying wavelengths and amplitudes. The optimum specular settings of the overhead point light source and the digital area-scan camera for effective highlighting of the imaged wheel path macrotexture were determined with an analytical formulation based on a simplistic and physically meaningful BRDF model. It was also shown that the images obtained by the theoretical formulation closely resemble those captured from a similarly textured experimental surface under identical lighting and imaging conditions. In particular, the pavement image formation model revealed that quantifiable changes in the brightness of images do occur due to changes in texture depth and spacing (wavelength). In the next phase of the study, the traffic induced pavement wearing process was simulated by gradual smoothening of the modeled surfaces and then images corresponding to each wearing stage were generated. The theoretically predicted variation of the image brightness due to wear was experimentally verified using images from a gradually worn out concrete specimen. Finally it was illustrated how the brightness evaluation of wheel path images has the potential to be a screening tool to monitor the degradation of macrotexture and hence the skid-resistance of pavements at the network level.
The primary findings of this research can be highlighted as follows. Models that provide estimate... more The primary findings of this research can be highlighted as follows. Models that provide estimates ofwet weather speed reduction, as well as analytical and empirical methods for the prediction of hydroplaning speeds of trailers and heavy trucks, were gathered and verified in a field study. The investigators have been able to provide Florida Dept. of Transportation (FDOT) with a predictive tool that combines the best of the available prediction models. Pavement properties needed to estimate the water film thickness produced during sheet flow were obtained from the literature and field studies. The investigators have been able to formulate analytical equations for predicting the critical water film thickness with respect to hydroplaning under different road geometric conditions, such as straight runs, super-elevations, and transition sections. A wet weather crash analysis was performed using crash statistics, geometrical data, pavement condition data, and other relevant information available in numerous FDOT databases. The results of this effort indicate that (i) wider sections are more likely to produce hydroplaning crashes, (ii) dense-graded pavements are more likely to induce conditions conducive to hydroplaning than open-graded ones, (iii) NCHRP's PAVDRN software would have predicted, to a significant degree of accuracy, most of the documented hydroplaning incidents, and (iv) the PAVDRN program is relatively unreliable for predicting hydroplaning in the inner lanes.
Retroreflective raised pavement markers (RRPMs) can provide lane and directional information at n... more Retroreflective raised pavement markers (RRPMs) can provide lane and directional information at night, particularly during wet weather conditions. In recent years, the RRPM service life in Florida has been generally shorter than expected. Moreover, the accuracy of current RRPM laboratory testing methods and procedures have been challenged. This report presents the research conducted over a two-year period to improve current RRPM designs and to develop new laboratory tests that can predict marker field performance. Current RRPM performance with typical failure modes and contributing factors were identified through literature review, nationwide questionnaire survey, and field survey. Finite element models (FEMs) of the tire/RRPM/pavement system were built to analyze the critical stress fields in RRPMs, for both field use scenarios and laboratory testing conditions, to explore the effects of various geometric features and material properties on critical stresses, and therefore to propo...
Industrial Innovation, 2008
Page 128. 7 Fusion of Vision Inertial Data for Automatic Georeferencing Duminda IB Randeniya Deci... more Page 128. 7 Fusion of Vision Inertial Data for Automatic Georeferencing Duminda IB Randeniya Decision Engineering Group Oak Ridge National Laboratory ManjrikerGunaratne Professor Dept. of Civil and Environment Engineering ...
Transportation Research Record: Journal of the Transportation Research Board, 2014
ABSTRACT
Dyna (Medellin, Colombia)
Knowing the 3-D behavior of friction coefficient (µ) vs. traveling speed (v) and wheel slip ratio... more Knowing the 3-D behavior of friction coefficient (µ) vs. traveling speed (v) and wheel slip ratio (s) on runway and highway pavements can facilitate the modern pavement engineers' job to a great extent. However, current methodology is limited to measuring µ at desired v and predicting it at different s values (at the same measured v) using 2-dimensional models. The paper presents a study carried out with friction data collected using Locked Wheel Skid Trailer (LWST) (ASTM E 274 Standard Test Method), to obtain the 3-D behavior of µ vs. v and s. An available 3-D friction model which is a combination of two well known 2-D friction models; Pennsylvania State University (PSU) model and Rado model, was used with LWST data collected in a field test on a wet asphalt pavement. The findings suggest that this method can provide reasonable predictions of µ for pavement management purposes.
SOILS AND FOUNDATIONS, 2000
ABSTRACT A semi-empirical computational technique is presented for predicting the depth of crater... more ABSTRACT A semi-empirical computational technique is presented for predicting the depth of craters formed by dynamic compaction (DC) pounders after the first impact. This technique utilizes a correlation developed between the initial shear strength of the soil beneath the pounder, determined by a CPT profile, and the impact energy per unit area (specific impact energy). First, the correlation is established by a series of model impact tests involving different drop heights, drop weights and impact areas. Then, the correlation is verified by the results from a full-scale field test performed by the authors. Further, data from a DC project performed elsewhere is also shown to support the predictive technique. An illustrative example is provided to demonstrate how typical CPT data can be adapted to predict the crater depths during DC projects for a given level of applied impact energy. On the other hand, this method can be used to determine the maximum impact energy that can be applied without causing excessive initial penetration of pounders and thus preclude the need for trial impacts. Hence well in advance of heavy equipment mobilization, this technique can certainly aid in effective planning of DC projects on particularly weak ground where penetration predominates heave.
Tire Science and Technology, 2010
Transportation Research Part C: Emerging Technologies, 2008
Effective integration of vision and inertial sensing can be used to overcome the classical issue ... more Effective integration of vision and inertial sensing can be used to overcome the classical issue of inertial divergence in inertial systems over time. However, for such integration, two types of calibration need to be performed, namely, (a) calibration to estimate the intrinsic properties of the vision cameras, such as the focal length and lens distortion parameters, and (b) determination of the transformation between the camera and the inertial system. While there are a variety of approaches to calibrate a camera optically, only a few accomplishments have been reported on calibration of cameras with inertial systems. Even the latter ones have been developed under indoor conditions. Calibration of a two sensor system under indoor conditions does not provide an appropriate and practical transformation for use in outdoor maneuvers due to invariable differences between outdoor and indoor conditions. Also, use of custom calibration objects in outdoor operational conditions is not feasible due to larger field of view that requires relatively large calibration object sizes. Hence calibration becomes a critical issue particularly if the integrated system is used in Intelligent Transportation Systems applications. In such cases it is essential that the two sensor system be calibrated in an outdoor setting in the final configuration of the vehicle. This paper introduces a calibration technique to determine the optimized transformation between the inertial and vision sensor systems in an outdoor setting. The derived intrinsic properties and the transformation between individual sensors are verified during two separate test runs on a section of an actual roadway. Finally, on a third roadway section the inertial and converted vision data are successfully compared with data from a manual survey performed.
![Research paper thumbnail of Erratum to "Calibration of inertial and vision systems as a prelude to multi-sensor fusion" [Transport. Res. Part C 18 (2008) 255-274] (DOI:10.1016/j.trc.2007.08.003)](https://attachments.academia-assets.com/44699728/thumbnails/1.jpg)
](Transportation Research Part C: Emerging Technologies, 2008
Transportation Research Record, 2000
Transportation Research Record, 2006
The Florida Department of Transportation (FDOT) has acquired and validated a multifunctional surv... more The Florida Department of Transportation (FDOT) has acquired and validated a multifunctional survey vehicle for the collection of highway pavement-related data at normal operating speeds. With its ability to collect pavement, right-of-way, and side-view images together with position location, cross-slope, grade, curvature, rutting, and roughness data, this state-of-the-art vehicle enables the rapid and automated evaluation of roadway performance and identification of hazardous conditions. Manual surveys that involve a high degree of subjectivity, a low production rate, and exposure to hazardous conditions are still the most widely used means for evaluating pavement distress. The pavement evaluation subsystem of the FDOT survey vehicle represents an efficient, cost-effective, and safe alternative for the collection and evaluation of pavement distress data. In the research reported in this paper, the precision and accuracy of the pavement imaging subsystem was tested under different lighting conditions, speeds, pavement types, and with or without the special pavement lighting system. The evaluation of pavement image quality has been achieved with the signal-to-noise ratio. Moreover, the effect of the vehicle's speed and the geometrical distortion in the image caused by optical distortion and distance measurement sensor error were also investigated. The conclusions and the recommendations drawn from this study can be used to identify the limitations of automated surveys and to determine the optimum conditions for the most accurate distress evaluation.
Digital image based automated pavement crack evaluation has been replacing the conventional manua... more Digital image based automated pavement crack evaluation has been replacing the conventional manual surveys due to its improved efficiency and safety. One popular principle employed in software used for automated detection of cracks from pavement images is based on identifying the intensity contrast between the images of the crack and the rest of the pavement surface. However, it has been observed that this technique results in other non-structural pavement surface irregularities being also detected as cracks, particularly in pavements with Open Graded Friction Courses (OGFC). This issue has a major impact on the accuracy of automated distress evaluation and hence software developers have constantly attempted to address this. Furthermore, since pavement management decisions are based on the crack evaluation results, the overestimation of cracks caused by detection of surface irregularities as cracks could cause improper prioritization of pavements and inefficient utilization of rehab...
The primary findings of this research can be highlighted as follows. Models that provide estimate... more The primary findings of this research can be highlighted as follows. Models that provide estimates ofwet weather speed reduction, as well as analytical and empirical methods for the prediction of hydroplaning speeds of trailers and heavy trucks, were gathered and verified in a field study. The investigators have been able to provide Florida Dept. of Transportation (FDOT) with a predictive tool that combines the best of the available prediction models. Pavement properties needed to estimate the water film thickness produced during sheet flow were obtained from the literature and field studies. The investigators have been able to formulate analytical equations for predicting the critical water film thickness with respect to hydroplaning under different road geometric conditions, such as straight runs, super-elevations, and transition sections. A wet weather crash analysis was performed using crash statistics, geometrical data, pavement condition data, and other relevant information available in numerous FDOT databases. The results of this effort indicate that (i) wider sections are more likely to produce hydroplaning crashes, (ii) dense-graded pavements are more likely to induce conditions conducive to hydroplaning than open-graded ones, (iii) NCHRP's PAVDRN software would have predicted, to a significant degree of accuracy, most of the documented hydroplaning incidents, and (iv) the PAVDRN program is relatively unreliable for predicting hydroplaning in the inner lanes.
Geotechnical and Geological Engineering, 1997
Dynamic replacement (DR) is a relatively new ground-modification technique that has been used suc... more Dynamic replacement (DR) is a relatively new ground-modification technique that has been used successfully to stabilize organic soil deposits by replacing the organic soil with sand columns. A full-scale DR field study was conducted in order to assess its effectiveness on Florida organic soils. A computer-based quality control system was developed using data-acquisition-management techniques to evaluate the degree of improvement
Published in 2006 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boc... more Published in 2006 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2006 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group No claim to original US Government works Printed in ...
Energy and Environment Research, 2015
International Journal for Numerical and Analytical Methods in Geomechanics, 1996
ABSTRACT Analytical determination of stresses and deformations caused by moving loads is vital to... more ABSTRACT Analytical determination of stresses and deformations caused by moving loads is vital to foundation and pavement designs. In current applications, moving loads are often approximated to be vertical impact loads. In this work, however, a live load is modelled as a uniform distribution of normal or shear stresses in actual motion. Then, a layer stiffness approach utilizing linear elasticity is followed in determining the surface and interior deformations due to the live load. By superimposing the two solutions for normal and shear surface stresses, the new approach can be made to provide an approximate solution to the problem of evaluating stresses and deformations caused by a wide wheel load rolling on a layered elastic system. Although elastic solutions in general are inadequate to explain the more significant consequences of pore pressure generation and dissipation in the soil subgrade, these results can certainly be useful to examine the shearing effects of wide rolling wheels on the asphalt layer and immediate settlement of the subgrade. It is found that the dynamic effects of a smoothly rolling wide load are significant at relatively low wheel velocities compared to those of shear waves in the subgrade and base.
Civil Engineering and Environmental Systems, 2011
The hazard potential of Sri Lanka's landslide-prone areas has bee... more The hazard potential of Sri Lanka's landslide-prone areas has been evaluated based on a well-defined decision process involving primary and secondary attributes. The relative contribution (weights) of both types of attributes and the severity ratings of secondary attributes have been defined subjectively on the same linguistic severity scale (‘very high’ to ‘very low’) based on expert judgement and past statistics,
Journal of Transportation Engineering, Sep 3, 2011
Modeling of the pavement image formation process using reflection properties of macrotexture show... more Modeling of the pavement image formation process using reflection properties of macrotexture showed that digital images of concrete pavements can be used to monitor pavement wear. The specific optical characteristics of images and the optimum camera settings that can be used for this purpose were determined by theoretically formulating the Bidirectional Reflection Distribution Function (BRDF) of surface texture with uniform color. In the analytical phase of the study, desired levels of pavement texture were generated by combining a series of 3-D sine surfaces of varying wavelengths and amplitudes. The optimum specular settings of the overhead point light source and the digital area-scan camera for effective highlighting of the imaged wheel path macrotexture were determined with an analytical formulation based on a simplistic and physically meaningful BRDF model. It was also shown that the images obtained by the theoretical formulation closely resemble those captured from a similarly textured experimental surface under identical lighting and imaging conditions. In particular, the pavement image formation model revealed that quantifiable changes in the brightness of images do occur due to changes in texture depth and spacing (wavelength). In the next phase of the study, the traffic induced pavement wearing process was simulated by gradual smoothening of the modeled surfaces and then images corresponding to each wearing stage were generated. The theoretically predicted variation of the image brightness due to wear was experimentally verified using images from a gradually worn out concrete specimen. Finally it was illustrated how the brightness evaluation of wheel path images has the potential to be a screening tool to monitor the degradation of macrotexture and hence the skid-resistance of pavements at the network level.
The primary findings of this research can be highlighted as follows. Models that provide estimate... more The primary findings of this research can be highlighted as follows. Models that provide estimates ofwet weather speed reduction, as well as analytical and empirical methods for the prediction of hydroplaning speeds of trailers and heavy trucks, were gathered and verified in a field study. The investigators have been able to provide Florida Dept. of Transportation (FDOT) with a predictive tool that combines the best of the available prediction models. Pavement properties needed to estimate the water film thickness produced during sheet flow were obtained from the literature and field studies. The investigators have been able to formulate analytical equations for predicting the critical water film thickness with respect to hydroplaning under different road geometric conditions, such as straight runs, super-elevations, and transition sections. A wet weather crash analysis was performed using crash statistics, geometrical data, pavement condition data, and other relevant information available in numerous FDOT databases. The results of this effort indicate that (i) wider sections are more likely to produce hydroplaning crashes, (ii) dense-graded pavements are more likely to induce conditions conducive to hydroplaning than open-graded ones, (iii) NCHRP's PAVDRN software would have predicted, to a significant degree of accuracy, most of the documented hydroplaning incidents, and (iv) the PAVDRN program is relatively unreliable for predicting hydroplaning in the inner lanes.
Retroreflective raised pavement markers (RRPMs) can provide lane and directional information at n... more Retroreflective raised pavement markers (RRPMs) can provide lane and directional information at night, particularly during wet weather conditions. In recent years, the RRPM service life in Florida has been generally shorter than expected. Moreover, the accuracy of current RRPM laboratory testing methods and procedures have been challenged. This report presents the research conducted over a two-year period to improve current RRPM designs and to develop new laboratory tests that can predict marker field performance. Current RRPM performance with typical failure modes and contributing factors were identified through literature review, nationwide questionnaire survey, and field survey. Finite element models (FEMs) of the tire/RRPM/pavement system were built to analyze the critical stress fields in RRPMs, for both field use scenarios and laboratory testing conditions, to explore the effects of various geometric features and material properties on critical stresses, and therefore to propo...
Industrial Innovation, 2008
Page 128. 7 Fusion of Vision Inertial Data for Automatic Georeferencing Duminda IB Randeniya Deci... more Page 128. 7 Fusion of Vision Inertial Data for Automatic Georeferencing Duminda IB Randeniya Decision Engineering Group Oak Ridge National Laboratory ManjrikerGunaratne Professor Dept. of Civil and Environment Engineering ...
Transportation Research Record: Journal of the Transportation Research Board, 2014
ABSTRACT
Dyna (Medellin, Colombia)
Knowing the 3-D behavior of friction coefficient (µ) vs. traveling speed (v) and wheel slip ratio... more Knowing the 3-D behavior of friction coefficient (µ) vs. traveling speed (v) and wheel slip ratio (s) on runway and highway pavements can facilitate the modern pavement engineers' job to a great extent. However, current methodology is limited to measuring µ at desired v and predicting it at different s values (at the same measured v) using 2-dimensional models. The paper presents a study carried out with friction data collected using Locked Wheel Skid Trailer (LWST) (ASTM E 274 Standard Test Method), to obtain the 3-D behavior of µ vs. v and s. An available 3-D friction model which is a combination of two well known 2-D friction models; Pennsylvania State University (PSU) model and Rado model, was used with LWST data collected in a field test on a wet asphalt pavement. The findings suggest that this method can provide reasonable predictions of µ for pavement management purposes.
SOILS AND FOUNDATIONS, 2000
ABSTRACT A semi-empirical computational technique is presented for predicting the depth of crater... more ABSTRACT A semi-empirical computational technique is presented for predicting the depth of craters formed by dynamic compaction (DC) pounders after the first impact. This technique utilizes a correlation developed between the initial shear strength of the soil beneath the pounder, determined by a CPT profile, and the impact energy per unit area (specific impact energy). First, the correlation is established by a series of model impact tests involving different drop heights, drop weights and impact areas. Then, the correlation is verified by the results from a full-scale field test performed by the authors. Further, data from a DC project performed elsewhere is also shown to support the predictive technique. An illustrative example is provided to demonstrate how typical CPT data can be adapted to predict the crater depths during DC projects for a given level of applied impact energy. On the other hand, this method can be used to determine the maximum impact energy that can be applied without causing excessive initial penetration of pounders and thus preclude the need for trial impacts. Hence well in advance of heavy equipment mobilization, this technique can certainly aid in effective planning of DC projects on particularly weak ground where penetration predominates heave.
Tire Science and Technology, 2010
Transportation Research Part C: Emerging Technologies, 2008
Effective integration of vision and inertial sensing can be used to overcome the classical issue ... more Effective integration of vision and inertial sensing can be used to overcome the classical issue of inertial divergence in inertial systems over time. However, for such integration, two types of calibration need to be performed, namely, (a) calibration to estimate the intrinsic properties of the vision cameras, such as the focal length and lens distortion parameters, and (b) determination of the transformation between the camera and the inertial system. While there are a variety of approaches to calibrate a camera optically, only a few accomplishments have been reported on calibration of cameras with inertial systems. Even the latter ones have been developed under indoor conditions. Calibration of a two sensor system under indoor conditions does not provide an appropriate and practical transformation for use in outdoor maneuvers due to invariable differences between outdoor and indoor conditions. Also, use of custom calibration objects in outdoor operational conditions is not feasible due to larger field of view that requires relatively large calibration object sizes. Hence calibration becomes a critical issue particularly if the integrated system is used in Intelligent Transportation Systems applications. In such cases it is essential that the two sensor system be calibrated in an outdoor setting in the final configuration of the vehicle. This paper introduces a calibration technique to determine the optimized transformation between the inertial and vision sensor systems in an outdoor setting. The derived intrinsic properties and the transformation between individual sensors are verified during two separate test runs on a section of an actual roadway. Finally, on a third roadway section the inertial and converted vision data are successfully compared with data from a manual survey performed.
Transportation Research Part C: Emerging Technologies, 2008
Transportation Research Record, 2000
Transportation Research Record, 2006
The Florida Department of Transportation (FDOT) has acquired and validated a multifunctional surv... more The Florida Department of Transportation (FDOT) has acquired and validated a multifunctional survey vehicle for the collection of highway pavement-related data at normal operating speeds. With its ability to collect pavement, right-of-way, and side-view images together with position location, cross-slope, grade, curvature, rutting, and roughness data, this state-of-the-art vehicle enables the rapid and automated evaluation of roadway performance and identification of hazardous conditions. Manual surveys that involve a high degree of subjectivity, a low production rate, and exposure to hazardous conditions are still the most widely used means for evaluating pavement distress. The pavement evaluation subsystem of the FDOT survey vehicle represents an efficient, cost-effective, and safe alternative for the collection and evaluation of pavement distress data. In the research reported in this paper, the precision and accuracy of the pavement imaging subsystem was tested under different lighting conditions, speeds, pavement types, and with or without the special pavement lighting system. The evaluation of pavement image quality has been achieved with the signal-to-noise ratio. Moreover, the effect of the vehicle's speed and the geometrical distortion in the image caused by optical distortion and distance measurement sensor error were also investigated. The conclusions and the recommendations drawn from this study can be used to identify the limitations of automated surveys and to determine the optimum conditions for the most accurate distress evaluation.