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This study was commissioned by INDOT to investigate the cost responsibility and revenue contribution of highway users with regard to the upkeep of Indiana's state and local highway infrastructure. For revenues, user and non-user sources were considered. The highway users were represented by the 13 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, ESALs, AASHTO loading equivalents, and PCEs were used; for allocating common costs, 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 currently underpaying or overpaying their cost responsibilities. 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 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.Pavement and bridge expenditures were found to have a dominant share of the overall expenditures on Indiana's highway system. 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 constitute a rather unstable funding situation particularly because the non-user sources are characterized by significant variability.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. The results of the equity analysis are generally consistent with those of studies carried out at other states.

Demand for vehicle and public transportation systems continues to increase in and around major urban centers. This increase is especially pronounced during the morning and evening commutes and is further complicated by the complex spatial interactions that influence the variation in system demand. In an effort to help agencies better understand this variability and develop better demand forecasts this research investigated the underlying factors impacting public transportation ridership regardless of transit mode, then uses this insight to estimate specific models to help forecast changes in subway ridership. The spatial database for the case study consisted of social, economic, and land use characteristics for the 2166 census tracts in the five boroughs of New York City, NY. The spatial models were found to have a better overall model fit compared to their non-spatial counterparts. Moreover, spatial dependence was found to be statistically significant in both models. Failure to account for spatial dependence in estimating public transportation use at the census tract or station level could lead to biased, inefficient or inconsistent parameter estimates. The completed research can help public agencies better address resource allocation by identifying locations that are over or underperforming in terms of expected ridership or identifying locations for network expansion.

The traditional methods of evaluating the compaction quality of pavement subbase and subgrade construction require considerable time and resources. Therefore, there is a need for a safe, reliable, rapid, and cost-effective field measurement technique for compaction testing of unbound pavement layers. The Light Weight Deflectometer (LWD) is one such mechanism that offers field measurement of deflections and stiffness of unbound pavement layers under a given load. The LWD is gaining increased attention for quality control and quality assurance (QC/QA) during pavement construction. The Indiana Department of Transportation (INDOT) is planning on implementing the LWD in field QA/QC for unbound layers of pavements. As such, this research investigates the feasibility of developing statistical limits for the compaction of specified combinations of subbase and subgrade materials in terms of their maximum allowable LWD deflections.Statistical limits were developed for six of the most common subgrade, subbase, or subgrade-subbase combinations that are used for highway pavement construction in Indiana: lime modified, cement modified, natural subgrade and No. 53 crushed stone (53CS) subbase overlaying these subgrades. For the subbase layers, these statistical limits are applicable only to six inches of subbase over subgrade and may not be applicable to a different layer configuration in terms of the number of lifts or thickness of lifts. The ultimate goal is for the developed statistical limits to replace the need for site-specific LWD limits derived from the onsite test sections, ultimately saving time and money.

The Matthew Hughes Commentary is the author's viewpoint on issues of christian relevance.

The Matthew Hughes Commentary is the author's viewpoint on issues of christian relevance.