Development of Speed-Related Ride Quality Thresholds Using International Roughness Index

2006 ◽  
Vol 1974 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Jianxiong Yu ◽  
Eddie Y. J. Chou ◽  
Jyh-Tyng Yau
Keyword(s):  
Ride Quality ◽  
International Roughness Index ◽  
Roughness Index

Full-Car Roughness Index as Summary Roughness Statistic

2005 ◽  
Vol 1905 (1) ◽  
pp. 148-156 ◽  
Author(s):  
Renato A. C. Capuruço ◽  
Tarek Hegazy ◽  
Susan L. Tighe ◽  
Sameh Zaghloul
Keyword(s):  
Mechanical Response ◽  
Pavement Management ◽  
Ride Quality ◽  
Management Decision ◽  
International Roughness Index ◽  
Front Suspension ◽  
Car Model ◽  
Roughness Index ◽  
Wheel Model ◽  
Management Decision Making

The international roughness index (IRI) and the half-car roughness index (HRI) are the two commonly used roughness indices for pavement management, decision making, prioritization, budgeting, and planning. This work presents a new statistic, termed the full-car roughness index (FRI), for calculation of roughness from longitudinal pavement profiles. FRI is calculated from a single, equivalent profile that is a composite of four corner profiles based on both civil and mechanical engineering principles. More specifically, the full-car (four-wheel) model combines the rear and front suspension systems through an interdependent relation of motion with the longitudinal axle. To validate this model, the FRI values for different pavement sections are determined for sampling roughness measurements from several states and provinces. Then, the behavior of FRI is compared with that of IRI and HRI. The methodology of assessment uses a Monte Carlo simulation for calibration and validation of the index. Correlations derived from this sensitivity analysis on the basis of regression analysis arrive at a conversion chart to propose conversion values from these indices to FRIs. Overall, this paper suggests that the mechanical response of the proposed full-car model is more representative of the characteristics of a real vehicle than the response of a quarter- or half-car model. The results also indicate that FRI is less sensitive to the governing factors that account for the quarter-car simulation and thus provides an index that is unique, insightful, and more effective in the characterization of ride quality.

scholarly journals Impact of Pavement Roughness on Traffic Safety under Heterogeneous Traffic Conditions

2020 ◽  
Vol 17 (1) ◽  
pp. 13-19
Author(s):  
M.O. Popoola ◽  
O.A. Apampa ◽  
O. Adekitan
Keyword(s):  
Traffic Safety ◽  
Road Traffic ◽  
Heterogeneous Traffic ◽  
Ride Quality ◽  
International Roughness Index ◽  
Traffic Crash ◽  
Traffic Conditions ◽  
Pavement Roughness ◽  
Roughness Index ◽  
Transportation Agencies

H ighway safety is a major priority for public use and for transportation agencies. Pavement roughness indirectly influence drivers' concentration, vehicle operation, and road traffic accidents, and it directly affect ride quality. This study focuses on analyzing the influence of pavement roughness on traffic safety using traffic, pavement and accident data on dual and single carriageway operated under heterogeneous traffic conditions in South-west, Nigeria. Traffic crash data between 2012 and 2015 was obtained from the Federal Road Safety Commission (FRSC) and International Roughness Index (IRI) data from the Pavement Evaluation Unit of the Federal Ministry of Works, Kaduna. Crash road segments represented 63 percent of the total length of roads. IRI values for crash and non-crash segments was a close difference of 0.3,This indicates that roughness is not the only factors affecting occurrence of traffic crashes but a combination with other factors such as human error, geometric characteristics and vehicle conditions. Crash severity was categorized into Fatal, serious and minor injury crashes. In all cases, the total crash rate increases with increase in IRI value up to a critical IRI value of 4.4 and 6.15 for Sagamu-Ore road and Ilesha-Akure-Owo road respectively, wherein the crash rate dropped. The conclusion is key in improving safety concerns, if transportation agencies keep their road network below these critical pavement conditions, the crash rate would largely decrease. The study concluded that ride quality does not directly affect traffic crash rate. Keywords: Pavement conditions, traffic safety, International Roughness Index, crash rate, carriageway.

Relating Pavement Condition Index and Present Serviceability Rating for Asphalt-Surfaced Pavements

2019 ◽  
Vol 2673 (3) ◽  
pp. 308-312 ◽  
Author(s):  
James Bryce ◽  
Richard Boadi ◽  
Jonathan Groeger
Keyword(s):  
Condition Index ◽  
Ride Quality ◽  
Concrete Pavements ◽  
International Roughness Index ◽  
Pavement Condition ◽  
Transportation Funding ◽  
Surface Transportation ◽  
Roughness Index ◽  
Pavement Condition Index ◽  
Using Data

In response to the two latest transportation funding authorization bills, the Moving Ahead for Progress in the 21st Century Act and the Fixing America’s Surface Transportation Act, rules that require the reporting of specific pavement condition measures have been developed and encoded into federal regulation. Pavement performance rules published to the federal register require the reporting of the International Roughness Index (IRI), percent cracking, rutting (for asphalt-surfaced pavements) and faulting (for jointed concrete pavements). Allowing that the measurement of the IRI on pavements with a speed limit below 40 mph is not expected to provide a reliable estimation of ride quality, the rules permit the reporting of the present serviceability rating (PSR) on these routes. However, many agencies do not measure the PSR or collect the slope variance data required to estimate the PSR. In light of not having the data required to directly estimate the PSR, this paper presents a model to estimate the PSR using data collected during a Pavement Condition Index (PCI) survey. Furthermore, this paper explores the reasons why pavements can have a good PCI and poor PSR and vice versa. The model presented in this paper provides a reasonable estimate of the PSR, though it is noted that agencies who wish to report PSR should conduct an updated assessment of rider satisfaction to develop a stronger correlation of PSR and PCI.

scholarly journals A Mechanical Vibration-induced Electric Energy Generation (MVEG) and Applications to Ride Quality of Vehicles and International Roughness Index (IRI)

2019 ◽  
Vol 6 (1) ◽  
pp. 59
Author(s):  
Schun T. Uechi ◽  
Hiroshi Uechi
Keyword(s):  
Energy Harvesting ◽  
Mechanical Vibration ◽  
Electric Energy ◽  
Road Surface ◽  
Ride Quality ◽  
International Roughness Index ◽  
Information Measurement ◽  
Roughness Index ◽  
Harvesting Method

A mechanical vibration-induced, electric energy harvesting method is discussed with applications to vibration analyses of systems of vehicles, motorboats, trains, machines and bridges, etc.. The research has evolved from the analysis of International Roughness Index (IRI), which studies roughness of road-surface as longitudinal vibrational motions in a vehicle measured with a quarter-car simulation (QCS) or Global Positioning System (GPS) with sensors such as gyro sensor and magnetometer sensor. The electric energy-convertible vibrations with information of roughness of road surface are extracted by way of an mechanoelectric energy conversion, and an energy harvesting technology suitable for the system of vehicles is discussed. The mechanical vibration-induced electric current is also suitable for IRI information measurement as well as a measure for ride quality of vehicles.

Acceptability of Pavement Roughness on Urban Highways by Driving Public

2003 ◽  
Vol 1860 (1) ◽  
pp. 187-193 ◽  
Author(s):  
Kevan Shafizadeh ◽  
Fred Mannering
Keyword(s):  
Empirical Support ◽  
Past Research ◽  
Ride Quality ◽  
International Roughness Index ◽  
Pavement Roughness ◽  
Road Roughness ◽  
Roughness Index ◽  
National Highway ◽  
User Acceptability ◽  
Highway System

The driving public’s attitude toward acceptable levels of road roughness is explored using empirical data collected on urban highways. Individual driver acceptability levels are matched with international roughness index (IRI) levels to examine the existence of potential user acceptability thresholds. In particular, the observed trends are compared with the federal IRI guideline of 170 in./mi (2.7 m/km) for acceptable ride quality recommended by FHWA in its 1998 strategic plan for the National Highway System. The research reported on appears to provide empirical support for the federal IRI guidelines that are already in existence. This study also found that IRI levels provided a very good indication of driver acceptability, which agrees with past research based on antiquated present serviceability ratings.

Effects of the International Roughness Index and Rut Depth on Crash Rates

2018 ◽  
Vol 2672 (40) ◽  
pp. 418-429 ◽  
Author(s):  
Michael Mamlouk ◽  
Mounica Vinayakamurthy ◽  
B. Shane Underwood ◽  
Kamil E. Kaloush
Keyword(s):  
Pavement Management ◽  
Ride Quality ◽  
International Roughness Index ◽  
Accident Rate ◽  
Crash Data ◽  
Crash Rates ◽  
Vehicle Operation ◽  
Roughness Index ◽  
Pavement Distresses ◽  
The Relationship

Pavement distresses directly affect ride quality, and indirectly contribute to driver distraction, vehicle operation, and accidents. In this study, analysis was performed on highways in the states of Arizona, North Carolina, and Maryland to investigate the relationship between accident rate and pavement ride quality (roughness) and rut depth. Two main types of data were collected: crash data from the accident records and International Roughness Index (IRI) and rut depth data from the pavement management system database in each state. Crash rates were calculated using the U.S. Department of Transportation method, which is the number of accidents per 100 million vehicle-miles of travel. Sigmoidal function regression analysis was performed to study the relationship between crash rate and both IRI and rut depth. In all cases, the crash rate did not show substantial increases until an IRI value of 210 inches/mile or a critical rut depth of 0.4 inches. When the IRI or rut depth increased above these values the crash rate increased. This is a key conclusion that provides empirically derived thresholds for IRI and rut depth to reducing the accident rate.

Travel Quality Assessment of Urban Roads Based on International Roughness Index: Case Study in Colombia

2017 ◽  
Vol 2612 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Daniel Abudinen ◽  
Luis G. Fuentes ◽  
Juan S. Carvajal Muñoz
Keyword(s):  
Travel Speed ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
User Perception ◽  
Iri Model ◽  
International Roughness Index ◽  
The Road ◽  
Pavement Surface ◽  
Road Condition ◽  
Roughness Index

Roughness is the main feature of the pavement surface that defines user comfort. Pavement roughness is generally defined as irregularities in the pavement surface that adversely affect ride quality, specifically user perception of the road condition. This paper highlights the limitations associated with the evaluation and implementation of the international roughness index (IRI) on urban roads. The paper focuses on ( a) roughness evaluation with full-scale profilers and ( b) conditions particular to urban roads—namely, traffic, intersections, and operating speeds. Given that the speed of urban networks is typically less than the 80 km/h used in the IRI quarter-car model, the implementation of the IRI model on urban roads was evaluated. Even though a given pavement surface reported a unique IRI value, user experience of the profile depended on the travel speed. This result was evidence that user perceptions of road condition are highly influenced by travel speed. The results suggested the need to develop a roughness index that captures the unique characteristics of urban roads and can estimate the road condition as perceived by users. For that reason, this research study focused on establishing thresholds for IRI on the basis of the weighted vertical acceleration parameter as an aid to assessing user perception. The proposed method allows the maximum allowable IRI value for a given road to be established on the basis of the road’s operational speed. The results indicated that IRI thresholds agreed with international and local Colombian standards.

Roadway-Vehicle Interaction, Physical Indexes, and Human Judgment of Ride Quality

1997 ◽  
Vol 1570 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Chiu Liu ◽  
Robert Herman
Keyword(s):  
Ride Quality ◽  
Physical Parameters ◽  
Human Judgment ◽  
International Roughness Index ◽  
Moving Vehicle ◽  
Roughness Index ◽  
Static Profile ◽  
Relationship Of ◽  
The Relationship ◽  
Analytical Expressions

Present serviceability index (PSI) modeling has been an important subject for decades. Other dynamic indexes characterizing a roadway such as the international roughness index (IRI), averaged rectified slope (ARS), and averaged rectified speed (ARV) have been proposed and studied. However, the roles played by these indexes in the interaction between road, vehicle, and human ratings have not been made clear. A unified physical model linking the static profile of a roadway and the dynamic response of a vehicle to the profile to the serviceability index of the roadway is presented here. Analytical expressions for jerk index, acceleration index, ARV, ARS, and IRI are derived from the developed model in terms of the physical parameters for roadways and the dynamic characteristics of a vehicle. Then a linear relation between the PSI and the logarithm of the jerk index is proposed. Using the jerk index computed from field profile data, the linear functional form for the PSI is verified, and regression R2 values higher than 0.94 are obtained for various types of pavements. The same analysis is performed for other dynamic indexes, and the R2 values are found to be approximately in the range from 0.70 to 0.80. These results indicate that the theoretical model correctly predicts and explains the human rating of ride quality and that the jerk experienced by raters in a moving vehicle dictates the ratings. Moreover, the relationship of the static parameters of roadway profiles with human ratings is discussed using the conventional approach.

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