Prototype Road Surface Management System

The Road Surface Management System (RSMS) is a powerful tool that can provide an overview and rough estimate of a roadway system’s condition at the network level and the approximate costs for future improvements in towns and small cities. This helps municipalities and local agencies to apply limited budget resources and provide the greatest road quality benefits. To control the cost of roadway surface deterioration, local agencies and municipalities need to make cost-effective decisions regarding the maintenance, rehabilitation, and reconstruction of the roadway network. RSMS can help in assessing the condition of the network, weighing alternatives, and establishing long-term treatment plans and budgets. In this paper, RSMS is used to evaluate a university campus road network in the state of Idaho and to establish the necessary repair methods for 10 selected sections in the campus network.

Investigating Road Safety Management Systems in the European Countries: Patterns and Particularities

A road safety management (RSM) system can be defined as “a complex institutional structure that involves cooperating and interacting bodies which support the tasks and processes necessary for the prevention and reduction of road traffic injuries”. RSM should promote the road safety progress of the country. However, the details of this relationship are generally lacking. This study explored the RSM systems in European countries based on the information collected through interviews with experts and officials, in each country, and using a “good practice” criteria questionnaire. The dataset included 14 countries with fifty items related to five RSM areas: institutional organization;policy formulation and adoption;policy implementation and funding;monitoring and evaluation;scientific support, information and capacity building. Cluster analyses and correlations were used to identify country groups with similar RSM components, to recognize typical RSM structures if available and to examine the relationship between RSM and road safety performance of the countries. The findings showed that all the countries are different when RSM systems are considered as a whole, making it impossible to identify typical RSM structures or a single best working model at a national level. However, it is possible to compare countries when the RSM areas are considered separately, where the clusters of countries recognized by the study present the patterns common for those European countries. Across the analyses, a number of countries with a consistently higher and lower availability of the RSM components were identified, enabling a final countries’ ranking into a number of groups. The latter actually reflects the level of RSM in the country, in terms of its correspondence to the “good practice” criteria. A further analysis indicated a positive correlation between the higher level of the RSM system and better safety performance of the countries.

A Probabilistic Approach to the Evaluation of Seismic Resilience in Road Asset Management

Road networks are classified as critical infrastructure systems.Their loss of functionality not only hinders residential and commercial activities,but also compromises evacuation and rescue after disasters.Dealing with risks to key strategic objectives is not new to asset management,and risk management is considered one of the core elements of asset management.Risk analysis has recently focused on understanding and designing strategies for resilience,especially in the case of seismic events that present a significant hazard to highway transportation networks.Following a review of risk and resilience concepts and metrics,an innovative methodology to stochastically assess the economic resources needed to restore damaged infrastructures,one that is a relevant and complementary element within a wider resilience-based framework,is proposed.The original methodology is based on collecting and analyzing ex post reconstruction and hazard data and was calibrated on data measured during the earthquake that struck central Italy in 2016 and collected in the following recovery phase.Although further improvements are needed,the proposed approach can be used effectively by road managers to provide useful information in developing seismic retrofitting plans.

Special issue: Management of road and railway traffic and transportation engineering

In recent years,with the development of road and railway transportation industries,a variety of complicated decisionmaking problems have emerged in real-world applications.It is urgent to analyze these problems from the perspective of theoretical and methodological innovations,and provide methods in management,decision-making and application so as to achieve efficient operations of traffic and transportation systems.These problems have

Value creation of road infrastructure networks:A structural equation approach

Although road agencies need to provide road infrastructure that is beneficial for road users, little is known about how the activities of the agencies influence the value creation of road infrastructure. From a service-dominant logic perspective, the importance of road main- tenance and traffic management activities for the contribution of road infrastructure to the value-creation process of road users is investigated. Road agencies facilitate the value creation of road users by maintaining, upgrading or renewing road infrastructure, the provision of information about the current traffic situation, possible redirection routes in case of traffic jams, and suggestions for appropriate driving behavior. Based on a structured questionnaire, data were collected among motorists in Singapore and analyzed by means of a partial least square modeling approach. The analysis revealed that road cleanliness and road evenness have a significant effect on the experience of road maintenance. Important and significant indicators for the experience of traffic management are the clarity of road signs and the efficiency of traffic redirection. A main conclusion of the research is that for traffic-intensive networks, both road maintenance and traffic man- agement activities are important contributors to the value creation of road infrastructure with a slightly stronger contribution of traffic management activities. Road agencies need to find appropriate maintenance strategies which reduce and coordinate simultaneous maintenance interventions on the network to such an extent that traffic management activities are able to minimize any considerable loss of traffic flow.

Prioritization methodology for roadside and guardrail improvement:Quantitative calculation of safety level and optimization of resources allocation

The attention to road safety-related issues has grown fast in recent decades. The experi- ence gained with these themes reveals the importance of considering these aspects in the resource allocation process for roadside and guardrail improvement, which is a complex process often involves conflicting objectives. This work consists on defining an innovative methodology, with the objective of calculating and analysing a numerical risk factor of a road. The method considers geometry, accident rate, traffic of the examined road and four categories of elements/defects where the resources can be allocated to improve the road safety （safety barriers, discrete obstacles, continuous obstacles, and water drainage）. The analysis allows the assessment of the hazard index, which could be used in decision- making processes. A case study is presented to analyse roadsides of a 995 km long road network, using the cost-benefit analysis, and to prioritize possible rehabilitation work. The results highlighted that it is suitable to intervene on roads belonging to higher classes of risk, where it is possible to maximize the benefit in terms of safety as consequence of rehabilitation works （i.e., new barrier installation, removal and new barrier installation, and new terminal installation）. The proposed method is quantitative; therefore, it avoids providing weak and far from reliable results; moreover, it guarantees a broad vision for the problem, giving a useful tool for road management body.

Investigating the influence of segmentation in estimating safety performance functions for roadway sections

Safety performance functions（SPFs） are crucial to science-based road safety management.Success in developing and applying SPFs, apart data quality and availability, depends fundamentally on two key factors： the validity of the statistical inferences for the available data and on how well the data can be organized into distinct homogeneous entities. The latter aspect plays a key role in the identification and treatment of road sections or corridors with problems related to safety. Indeed, the segmentation of a road network could be especially critical in the development of SPFs that could be used in safety management for roadway types, such as motorways（freeways in North America）, which have a large number of variables that could result in very short segments if these are desired to be homogeneous. This consequence, from an analytical point of view, can be a problem when the location of crashes is not precise and when there is an overabundance of segments with zero crashes. Lengthening the segments for developing and applying SPFs can mitigate this problem, but at a sacrifice of homogeneity. This paper seeks to address this dilemma by investigating four approaches for segmentation for motorways, using sample data from Italy. The best results were obtained for the segmentation based on two curves and two tangents within a segment and with fixed length segments. The segmentation characterized by a constant value of all original variables inside each segment was the poorest approach by all measures.

An optimization model for improving highway safety

This paper developed a traffic safety management system （TSMS） for improving safety on county paved roads in Wyoming. TSMS is a strategic and systematic process to improve safety of roadway network. When funding is limited, it is important to identify the best combination of safety improvement projects to provide the most benefits to society in terms of crash reduction. The factors included in the proposed optimization model are annual safety budget, roadway inventory, roadway functional classification, historical crashes, safety improvement countermeasures, cost and crash reduction factors （CRFs） associated with safety improvement countermeasures, and average daily traffics （ADTs）. This paper demonstrated how the proposed model can identify the best combination of safety improvement projects to maximize the safety benefits in terms of reducing overall crash frequency. Although the proposed methodology was implemented on the county paved road network of Wyoming, it could be easily modified for potential implementation on the Wyoming state highway system. Other states can also benefit by implementing a similar program within their jurisdictions.