All responsibility rests with the end user for using anything in these files. Comprehensive book on the modelling of road user and environmental effects. It covers all aspects from vehcile operating costs to emissins.
The models presented here formed the basis for the modelling in HDM-4, although the software does not fully implement the models. The report addresses a range of issues from Information Quality through calibrating pavement deterioration and road user effects. Applications 70 Documents. Ul-Islam et al. Calibration factors were estimated for the parts consumption and labour hours for the VOC relationships; and for the nitrous oxide, carbon monoxide, hydrocarbon, particulates, carbon dioxide and sulphur dioxide exhaust for emissions relationships.
It was found that the use of HDM-4 default parameters overestimates both the parts consumption and labour hours in comparison to the actual consumption in Japan for all the five vehicle types considered. Yet, the estimates of the exhaust emissions were found to be less for some vehicles and high for others.
The study also showed that the fuel consumptions predicted by HDM-4 model is significantly higher than the observed values by the Mitsubishi Research Institute MRI for the four vehicle types at different speeds, but the shape of the two fuel consumption curves are very similar for all vehicle types.
The study also showed the significant difference between HDM-4 fuel consumption prediction and the MRI observation, but there was a strong agreement between the calibrated HDM-4 prediction and the actual values as shown in Figure 5.
Using the fuel consumption data observed in two similar free-flow studies conducted in Canada and Chile, Altamira et al. The reliability of the RUE model can be obtained when it is appropriately calibrated into the local conditions. However, other relationships such as speed and capacity relationships need to be considered for the capacity of calibration and the reliability of the RUE outputs corresponding to various conditions, especially, for mixed traffic with prevailing motorcycle such as in Vietnam, Laos, and Cambodia.
Furthermore, the sub-model of engine revolutions proposed in HDM4 need to be verified, due to the differences between the predicted and observed data as indicated by Altamira et al. The roughness-environment factor is the most important due to a high potential net impact, followed by the cracking initiation, cracking progression, and rut depth progression factors as shown in Table 5.
For road deterioration, environmental conditions have a strong influence, affecting deterioration rates by factors of up to 2 or 3 between the extremes of hot arid and cold wet climates. Local construction materials, practices and quality also affect deterioration rates and the effectiveness of maintenance. As these factors vary from region to region, therefore, both influences can be controlled through calibration factors in the inputs to HDM, in addition to the main traffic and pavement input parameters.
De Solminihac et. As a result, it offers the possibility of relying upon a broader inference space and the possibility of integrating data gathered in previous studies with the new data.
Moreover, this methodology permits section distress measurements to be made in a brief period of time, and consequently allows for the evaluation of a greater number of sections and categories. Using this methodology for the available data observed from to in Akita prefecture Japan , Nishio and Tsunokawa calibrated the RDWE model for six factors mentioned above and compared with the prediction models proposed by Japan Infrastructure and Transportation Ministry ITM. On the other hand, Okubo et al.
Therefore, besides calibrating the model according to the specific conditions of a country or region where they are to be used, more extensive efforts for verifying road deterioration models are recommended to increase the predictability of the models and increase the possibility of conducting an efficient highway management process.
Source: Bennett and Paterson, 5. Besides supporting the data for HDM-4—based analysis, systematic collection and management of data may help highway agencies in better establishing the strategies to calibrate, verify, and update the HDM-4 models into local conditions. Network Road Years of last preventative maintenance, last Maintenance re-gravelling, last resurfacing, last rehabilitation, and History last construction.
The paper tackled several practical issues involved in executing strategy and project analyses using HDM-4 that have not been thoroughly considered in the past. The paper provides guidelines on using the length of the analysis period for HDM-4 strategies analysis and presents an approach to the true optimization of pavement maintenance options using HDM-4 combined with gradient methods. The issues raised and the findings presented in this paper are useful for users of HDM-4 involved in both strategy and project level analyses.
In addition, the paper shows the future directions in order to apply HDM-4 effectively according to the Vietnamese conditions. Special Report Nos. C, USA. Abaynayaka, S. Morosiuk, and H. Proceedings of the Institution of Civil Engineers.
Altamira, A. Harrison, and J. Covarrubias Archondo-Callao, R. The World Bank, Washington D. The World Bank , Washington D. The United States of America. Bennett, C. Paterson Volume V: A guide to Calibration and Adaptation. HDM-4 Manual Version 1. Biggs, D. Australian Road Research Board. Research Report Vermouth South, Vic.
Chesher, A. Harrison Highway Design and Maintenance Standards Series. Cundill, M. Transport Research Laboratory, Crowthorrne, U. De Solminihac, H. Hidalgo, and M. Salgado Eric Stannard ISDP The Final Report. Vietnam Ministry of Transportation, Hanoi, Vietnam. Final report, 12 volumes, Brasilia, Brazil. Harral, C. Hide, H. Hiep, V. If, for example, the objective function is to maximise the Net Present Value NPV , the problem can be defined as: Select that combination of treatment options for sections that maximises NPV for the whole network subject to the sum of the treatment costs being less than the budget available.
The HDM-4 programme analysis application may be used to prepare a multi-year rolling programme, subject to resource constraints see Figure 5. This provides an efficient and robust index for prioritisation purposes. Indices such as the NPV, economic rate of return ERR , or predicted pavement condition attributes for example, road roughness are not recommended as ranking criteria. Overview of HDM-4 17 Version 1.
The application analyses a road link or section with user-selected treatments, with associated costs and benefits, projected annually over the analysis period. Economic indicators are determined for the different investment options. Project analysis may be used to estimate the economic or engineering viability of road investment projects by considering the following issues:! The structural performance of road pavements!
Life-cycle predictions of road deterioration, road works effects and costs! Road user costs and benefits! Economic comparisons of project alternatives Typical appraisal projects would include the maintenance and rehabilitation of existing roads, widening or geometric improvement schemes, pavement upgrading and new construction.
There are no fundamental changes to the philosophy of the system in this area, but improved road deterioration relationships have been extended to cover a wider range of pavements and the performance of materials in temperate and cold climates.
Road user cost relationships include impacts on road safety. In terms of data requirements, the key difference between the strategy and programme analyses, with that for project analysis, is in the detail at which data is defined.
Overview of HDM-4 19 Version 1. The three analysis tools Strategy, Programme and Project operate on data defined in one of four data managers:! Road Network Defines the physical characteristics of road sections in a network or sub-network to be analysed. Vehicle Fleet Defines the characteristics of the vehicle fleet that operate on the road network to be analysed.
Road Works Defines maintenance and improvement standards, together with their unit costs, which will be applied to the different road sections to be analysed. HDM Configuration Defines the default data to be used in the applications. A set of default data is provided when HDM-4 is first installed, but users should modify these to reflect local environments and circumstances.
Technical analysis within the HDM-4 is undertaken using four sets of models:! RD Road Deterioration Predicts pavement deterioration for bituminous, concrete and unsealed roads. WE Works Effects Simulates the effects of road works on pavement condition and determines the corresponding costs. The model simulates, for each road section, year-by-year, the road condition and resources used for maintenance under each strategy, as well as the vehicle speeds and physical resources consumed by vehicle operation.
After physical quantities involved in construction, road works and vehicle operation are estimated, user-specified prices and unit costs are applied to determine financial and economic costs.
Relative benefits are then calculated for different alternatives, followed by present value and rate of return computations. The HDM-4 system is designed to interface with external systems such as:!
Databases Road network information systems, pavement management systems, etc. Overview of HDM-4 20 Version 1. Technical models Accessed directly by external systems for research applications or other studies. The system design is modular in structure to enable users to implement the HDM-4 modules independently within their road management systems. The technical relationships can easily be calibrated to match local conditions by using HDM-4 Configuration in addition to country specific default data.
For example, pavement condition data collected by visual inspection according to condition classes for example, Very good, good, fair, poor condition can be converted to the HDM-4 model requirements prior to running any of the applications see section below on Importing and Exporting Data.
Similarly, HDM-4 can work with very detailed measurements of pavement condition if the data is available. This flexibility in data requirements should permit all potential users with a variety of data to integrate HDM-4 into their road management functions. For further details, refer to Applications Guide - Volume 2. Default data and calibration coefficients can be defined in a flexible manner to minimise the amount of data that must be changed for each application of HDM Default values are supplied with HDM-4, but these are all user-definable and facilities are provided to enable this data to be modified.
The HDM-4 set of tools may be used as additional modules to current pavement management systems. Import and Export functions, built into the modules, provide a mechanism for data transfer between existing databases and HDM-4 modules. The data exchange format uses standard data file formats to encourage its wide adaptation by road organisations. It allows users to define different networks and sub-networks, and to define road sections, which is the fundamental unit of analysis.
The data entities supported within the road network are:! Sections Lengths of road over which physical characteristics are reasonably constant. Links Comprise one or more sections over which traffic is reasonably constant. This is provided for purposes of compatibility of the network referencing system with existing pavement management systems. Nodes Intersections which connect links or other points at which there is a significant change in traffic, carriageway characteristics, or administrative boundaries.
All network data is entered using the Road Network folder, and facilities are also available for editing, deleting and maintaining this data. The approach to network referencing is considerably more flexible than that used in HDM-III, and is designed to handle a wide range of external referencing conventions as might be used by other systems with which HDM-4 may need to interface. Overview of HDM-4 22 Version 1. The method used to represent a vehicle fleet is considerably more adaptable than that used in HDM-III with no limit on the numbers or types of vehicles that can be specified.
Motorcycles and non-motorised vehicles are included. Multiple vehicle fleet data sets can be set up for use in different analyses, with a wide range of default data provided. Road organisations normally set up different standards that can be applied in practical situations in order to meet specific objectives which are related to functional characteristics of the road network system.
The Road Works folder provides facilities, within a flexible framework, to define a list of maintenance and improvement standards that are followed by road organisations in their network management and development activities. The standards defined in the Road Works Standards folder can be used in any of the three analysis tools:! Project analysis! Programme analysis! Strategy analysis 7.
The data import into HDM-4 as well as the export from HDM-4 is organised according to the data objects described above that is, road networks, vehicle fleets, maintenance and improvement standards, HDM Configuration.
The physical attributes of the selected data objects must be exported to a data exchange file format defined for HDM This permits all data required by HDM-4 to be imported directly from any database.
Data transformation rules may need to be implemented for converting the data held in the external database to the format used by HDM- 4. For example, pothole data recorded in the external database in terms of the percentage area of the pavement surface would need to be converted to the equivalent number of standard pothole units 10 litres by volume required in HDM Similarly, other data required by HDM-4, such as pavement deterioration calibration factors, should be inserted as pre-defined default values according to the type of pavement, road class, and other defined factors.
These include data on vehicle fleet characteristics, road maintenance and improvement standards, unit costs and economic analysis parameters for example, discount rate, analysis period, etc. Overview of HDM-4 23 Version 1. This has been achieved by addressing the user interface design and data requirements. The user interface has been improved by developing the system to run under a standard Microsoft Windows environment. Many computer users are already familiar with the Windows system and this should make learning HDM-4 more intuitive.
A modular system design has been adopted to enable different modules to be used relatively easily and to facilitate future system operation on other non-Windows platforms.
More details of system issues are described in the Software User Guide - Volume 3. Considerable attention has also been paid to the data that must be entered by users, particularly because the total data requirement is greater than that in HDM-III in order to allow for the extended facilities included in HDM The concept of data hierarchy is used, whereby default data is defined for many items in HDM Configuration, and users can choose the extent to which defaults are used.
The system can be used with a level of data entry detail that is appropriate for particular applications. A comprehensive Help system is also provided. Figure 8. Detailed instructions for the operation of the individual modules are given in the Software User Guide - Volume 3. Overview of HDM-4 24 Version 1. Overview of HDM-4 26 Version 1. Proceedings of the Institution of Civil Engineers. Archondo-Callao, R. Cundill, M. In: TRB. FHWA, Highway economics requirements system.
Geipot, Research on the interrelationships between costs of highway construction, maintenance and utilisation PICR. Final report, 12 volumes, Brasilia, Brazil. Harral, C.
Hide, H. Crowthorne: Transport and Road Research Laboratory. Hoban, C. Technical Paper Number Kerali, H. London: Institution of Civil Engineers. Overview of HDM-4 27 Version 1. South Africa: University of Pretoria. Moavenzadeh, F. Cambridge Mass: Massachusetts Institute of Technology. Morosiuk, G. Parsley, L. Paterson, W. Phillips, S. Robinson, R. Danielsson U.
Basingstoke and London: Macmillan Press. Watanatada T. Baltimore: Johns Hopkins for the World Bank. Overview of HDM-4 28 Version 1. A recent pavement condition survey has shown that Traffic surveys were also carried out in the previous year. Following an analysis of the data available together with the characteristics of the national road network, it has been decided to categorise the paved road network into three traffic classes high, medium, low , and three pavement condition classes good, fair, poor , and the unpaved road network has been categorised into two traffic categories only medium and low.
The resulting road network matrix is summarised in Table A. Overview of HDM-4 29 Version 1. The HDM-4 procedure required to analyse the national road network comprises the following:! Create the representative road network matrix using the Strategy application;!
Define the characteristics of the vehicles which use the road network;! Specify traffic growth rates;! Assign the maintenance and improvement standards to the road network matrix together with their unit costs;! Run the HDM-4 Strategy application to determine the total budget requirement;! Carry out constrained budget analyses;! Review reports and graphs of the analyses conducted.
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