Matthew Volovski

Comparative Evaluation of Public-Private Partnerships in Roadway Preservation

In a bid to reduce overall costs, manage risks, and attract private capital, highway agencies worldwide strive to increase private-sector participation in road infrastructure development, particularly at the developmental phases of construction and preservation. A common mechanism for private-sector participation is the concept of a public–private partnership (PPP). As agencies grapple with the decision about whether to adopt a specific PPP or the traditional contracting approach for a specific project, they lack a rational decision-support structure. In addressing this major gap in PPP-related literature, this paper presents a framework by which an agency may assess the performance (relative benefits) of different PPP contracting approaches for highway preservation. For the purposes of this paper, performance is expressed in relation to the likelihood and intensity of cost savings calculated with data from domestic (U.S.) and international projects. In addition, the influence of project and contract attributes (such as the expected project duration, work type, and project size) on PPP project performance is investigated. The framework can be used or duplicated by highway-related agencies and international organizations for identifying the superior contracting option for a given road preservation project on the basis of project characteristics and for quantifying the consequences of such choices for cost savings or other performance criteria.

Performance Evaluation and Life Prediction of Highway Concrete Bridge Superstructure across Design Types

AbstractManagers of highway bridge infrastructure constantly seek to improve their predictions of the physical performance of their facilities at any future time and also to identify the influentia...

Rolling stock purchase cost for rail and road public transportation: random-parameter modelling and marginal effect analysis

ABSTRACT Public transportation rolling stock is a major item of capital expenditure associated with transit facility construction, expansion, or revitalisation. As such, reliable estimates of the expected purchase costs of rolling stock are critical for analysing the financial feasibility of proposed public transportation systems and financial planning for existing systems. Such cost data are often characterised by heterogeneity of observations that often plagues fixed parameter (FP) model estimation. Therefore, in modelling transit rolling stock costs, it is needed to address such limitations of past studies. Using data from the National Transit Database, this paper addresses the issue through the random parameter (RP) estimation modelling technique, where parameter estimates are allowed to vary across observations according to the most appropriate distribution. The paper demonstrates that the RP modelling technique yields superior estimates compared to the FP model. This is because the former can account for unobserved heterogeneity in transit rolling stock purchase cost data due to unobserved factors that otherwise severely impair the reliability or intuitiveness of the model. The paper also carries out marginal effect and sensitivity analyses on the developed model to acquire a deeper insight into the influence of the cost factors. The RP rolling stock cost models developed in this paper can be applied by public transportation agencies to carry out strategic tasks associated with the development or management of new or existing transit systems, respectively. These tasks include analyses of financial feasibility of proposed transit systems, development of budgets, and projections of cash outflows as part of long-range plans, financial planning, and short- and long-term funding needs assessment for existing or proposed transit systems. Moreover, the findings regarding the influential cost factors can be used to guide purchasing policies for transit rolling stock.

Use of Kriging Estimation to Enhance the Integrity of Geospatial Climate Data for Infrastructure Management

Roadway pavements, one of the largest transportation infrastructure asset classes in terms of total value, deteriorate over time because of load (traffic) and nonload (climate) factors. Research studies over the years have shown that the nonload share of pavement damage can be as high as 60%. Historically, deterioration modeling has used coarse climate data extracted from regional or national climate maps because of insufficient local data or lack of efficient processes to refine the data. Many national and state databases contain significantly coarse climate data, and when such data are used in deterioration and cost models, the potential exists for significant misspecification. To address the problem, this paper implements kriging estimation, a geostatistical method that uses the spatial distance and autocorrelation of data collection sites to impute unobserved data values within a random field. Kriging estimation can produce gradient maps of the geospatial variable as well as point predictions of the variable at locations along a linear path such as a roadway centerline. This paper presents a case study of I-65 in Indiana, which used data from 59 statewide weather stations of the National Oceanic and Atmospheric Administration. The use of kriging estimation yielded a continuous prediction curve along the roadway centerline, which was an improvement over the discrete and coarse steplike nature of traditionally reported climate data.

Developing statistical limits for using the light weight deflectometer in pavement construction quality assurance

Traditional methods of evaluating the quality of pavement subbase and subgrade compaction require considerable time and resources. Therefore, agencies continue to seek and evaluate safe, reliable, rapid, and cost-effective alternatives for quality assurance of the field compaction of unbound pavement layers. The light weight deflectometer (LWD) is a promising alternative that is increasingly gaining attention. This study investigated the feasibility of developing statistical limits for the compaction of specified combinations of subbase and subgrade materials in terms of their LWD maximum allowable deflections (MAD), to replace the need for site-specific LWD limits derived from the onsite test sections. Statistical limits were developed for six common subgrade and subgrade–subbase combinations used for highway pavement construction: lime-modified, cement-modified, and natural subgrade and the first six-inch lift of Number 53 crushed stone subbase overlaying these subgrades. Two sources of data, test sections and acceptance tests, were used. For a given material type, the data from the former exhibited less variability between projects. The test section data yielded MADs that did not vary significantly between projects for cement- and lime-modified subgrade, non-modified subgrade, and six inches of Nr.53 crushed stone over lime-modified subgrade.

Costs and benefits of highway resurfacing: a case study of Interstate 465 in Indiana, USA

Highway restoration projects reduce subsequent agency maintenance costs while providing user and community benefits through travel time savings, safety enhancement and reduced emissions. However, i...

Addressing the Local-Road VMT Estimation Problem Using Spatial Interpolation Techniques

AbstractVehicle miles of travel (VMT) data have a wide range of applications in highway agency business processes. However, at all administrative levels, highway agencies continue to be stymied by ...

Estimation of Routine Maintenance Expenditures for Highway Pavement Segments: Accounting for Heterogeneity Using Random-Effects Models

AbstractA significant portion of highway infrastructure life-cycle costs can be attributed to maintenance expenditures, particularly in the later years of an infrastructure’s life. These expenditur...

Indiana State Highway Cost Allocation and Revenue Attribution Study and Estimation of Travel by Out-of-State Vehicles on Indiana Highways

This study was commissioned by Indiana Department of Transportation (INDOT) to investigate the cost responsibility and the revenue contribution of highway users with regard to the upkeep of Indiana’s state and local highway infrastructure (pavements, bridges, safety assets, and mobility assets). The costs consisted of expenditures on construction, preservation, maintenance, and operations of the highway infrastructure. For revenues, user and non‐user sources were considered. The highway users were represented by the 13 Federal Highway Administration (FHWA) vehicle classes, and the study was based on 2009‐2012 data on expenditures and revenues. The study framework duly recognized the dichotomy between attributable and common costs. For allocating the attributable costs to the vehicle classes, equivalent single axle loads (ESALs), American Association of State Highway and Transportation Officials (AASHTO) loading equivalents, and passenger car equivalents (PCEs) were used; for allocating common costs, vehicle miles traveled (VMT) was used. For each vehicle class, the share of revenue contribution was compared to the share of cost responsibility to determine respective equity ratios and thus to ascertain the extent to which vehicles in each class may be underpaying or overpaying their cost responsibilities at the current time. The study also determined the distribution of fuel purchases and travel by out‐of‐state vehicles on Indiana’s highways; this analysis was required to further refine the results of the cost allocation and also to quantify the magnitude of any imbalance between the out‐of‐state travel and share of consumption on Indiana’s infrastructure and the revenue from such out‐of‐state vehicles. The outcome of this research is a systematic documentation of the sources and extents of highway revenues and the areas of expenditures at the local and state levels in Indiana. Pavement and bridge expenditures were found to have a dominant share of the overall expenditures on Indiana’s highway system. Classes 2 (automobiles) and 9 (5‐axle combination trucks) were found to have a dominant share of the cost responsibilities. It was determined that the user revenue sources contributed approximately 63.5% of the total state funding for highway expenditures and 36.5% were from non‐user revenue sources. The inability of user revenue sources to cover the total highway expenditure and the consequent partial reliance on non‐user sources seem to constitute a rather unstable funding situation particularly because the non‐user sources are characterized by significant variability. On the basis of the expenditures and revenues associated with the various user groups (vehicle classes) over the analysis period, this study found that inequities exist, albeit in varying degrees, among the highway user groups. Of the 13 vehicle classes, classes 1–4 were found to be overpaying their cost responsibilities while classes 5–13 are underpaying. For example, vehicle class 2 is overpaying its cost responsibility by 10% while vehicle class 9 is underpaying by 19%. The results of the equity analysis are generally consistent with those of studies carried out at other states. Also, it was estimated that the travel by out‐of‐state vehicles on Indiana’s interstates, national highway system (NHS) non‐interstates, non‐NHS and local roads are 21%, 10%, 9%, and 7% respectively, of the total travel as a percentage of VMT on those families of highway systems.