About the research
The objective of the proposed guidelines for a roadway management system (RMS) is to describe a framework for a modular and user-friendly RMS that will assist local government agencies of all sizes in coordinating and planning routine and preventive maintenance, rehabilitation, and reconstruction. These guidelines include a step-by-step procedure to establish a customized RMS for local government agencies. The resulting RMS, based upon the proposed guidelines, will be a systematic methodology that can assist local government agencies to evaluate current pavement conditions, identify problems on pavements, select the best repair and maintenance strategies with the minimum cost, and generate a schedule and priority program for these actions at both project and network levels at both the present time and the future.
As part of these guidelines, we also report the results of a nationwide survey of local government roadway management practices. A questionnaire was developed as part of this survey and sent out to local government agencies throughout the United States. This information was then used to establish the proposed RMS guidelines that are relevant for local government agencies? needs and expectations. In addition, a literature survey was conducted to review current roadway management systems and research, and to reduce the duplication of research, information, or training materials that have been developed by other government agencies or private consultants. Furthermore, the information from both survey methods was evaluated, refined, and customized to the proposed RMS guidelines.
Detailed background information on various aspects of a roadway pavement and an RMS is also given in these guidelines to ensure consistency of usage and understanding since these terms and definitions may vary from one agency to another. The information includes definitions and terms related to pavements, types of pavement, types of pavement distress, etc.
Then, a section on inventory methodology is included. An inventory methodology is established for use in the data collection process. It is imperative that only necessary information be collected to reduce time and cost in the data collection process. This section also provides terms and definitions used in the inventory program, referencing and defining methods for the roadway network, and the understanding between project and network levels. This information is expected to clarify the scope and level of responsibility for local government agencies.
Once the data inventory is established, the data collection process can be initiated to gather information from concerned pavements within the roadway network. The data used to evaluate the current pavement condition can be obtained by a variety of methods such as visual inspection rating, nondestructive testing, destructive testing, and others. Moreover, there are several mathematical indices that indicate the current pavement condition and that are widely used by local government agencies, such as the Present Serviceability Index (PSI), International Roughness Index (IRI), and Pavement Condition Index (PCI). These guidelines also provide the step-by-step procedure to obtain the PCI value for different low-volume flexible and built-up pavement types as well as different maintenance strategies. In the proposed guidelines, the PCI value forms the basis for establishing the other components as well as developing the coordination among the components of an RMS.
The integration of an RMS with a geographical information system (GIS) is another approach to achieve the long-term use of an RMS by updating the data on pavements within the roadway network. This report presents the advantages acquired from the integration of an RMS with GIS as a platform, details of systems displaying RMS information on maps, components of GIS, and the approach to establish a central database.
Furthermore, these guidelines present a method to generate the maintenance, rehabilitation, and reconstruction actions in order to maintain and improve the pavement performance based upon the PCI obtained earlier. This will help local government agencies to decide what repair and maintenance actions would be best suitable for concerned pavements.
Without a pavement performance prediction model, the future tasks and schedules cannot be effectively planned. A pavement performance prediction model is developed based upon the collected data on pavements to forecast the PCI value in the future. Therefore, by using this prediction model local government agencies will be able to predict future facility condition, analyze facility life cycle cost, and estimate the type and timing of maintenance and rehabilitation need regarding only the projected PCI.
There are a number of factors used to consider maintenance alternatives needed for pavements such as cost, duration of action, available resource, etc. Generally, the cost of each alternative is the primary factor that most local government agencies are concerned with due to the limited funding each year. In order to compare the cost of each strategy, life cycle cost analysis can be preformed. Consequently, a methodology for life cycle cost analysis is also provided in these guidelines.
Usually, local government agencies do not have enough funds to improve all segments within a roadway network although they have adequate information to identify problems on these segments. The priority program, therefore, is the solution for local government agencies to generate their budget and to numerically plan which concerned segment should be first taken care of. These guidelines identify the numerous factors affecting the priority index such as PCI, average daily traffic, roadway functional classification, roadway location, maintenance history, and pavement riding quality, and provide a methodology for obtaining the priority indices.
The final component of an RMS is to generate a report such that the elected board or council can approve the funds regarding local government agencies? needs. It is imperative that the data and analysis be clear and easy to understand for those who are not technical experts or engineering professionals. These guidelines briefly demonstrate the tasks that should be considered and included in the proposed report. This will guide local government agencies to establish the proposed report for their own customized RMS.
U.S. Department of Transportation