Review of Methods for Estimating the Economic Impact of Transportation Improvements

Transportation analysts and the public decision-makers they support are confronted with a broad range of analytical tools for estimating the economic impacts of improvements to trans- portation networks. Many of the available models operate at different scales and have distinctly different structures, making them more or less appropriate for analyzing the impacts of differ- ent types of projects. Here, we review several of the economic methods and models that have been developed for analyzing the impact of transportation improvements, giving special atten- tion to types of projects that add highway capacity in urban areas. We review project-based methods, including beneÞt-cost analysis and several analytical software tools developed by the Federal Highway Administration (FHWA) for economic analysis of transportation investment. We then move on to aggregate and disaggregate-level econometric methods, including regional economic models, hedonic price functions, production functions and cliometric analyses. We also devote some attention to the role of induced demand in economic evaluation, since it is of- ten one of the most uncertain and confounding factors faced by those charged with conducting economic evaluation of transportation projects.Economic Impact, Benefit-Cost Analysis

Predicting Land Use Change: How Much Does Transportation Matter?

In this paper, we propose to measure the extent of the inßuence of transportation systems on land use change. Using a set of high-resolution land use data for the Twin Cities metropolitan region, we estimate logistic regression models of land use change covering a 10-year period from 1990 to 2000. The models account for existing land use types, neighboring land uses, and transportation network variables that measure the physical proximity of highway networks, as well as the level of accessibility associated with a speciÞc location. The models are esti- mated with and without the transportation variables and compared to assess the extent of their inßuence. We Þnd (perhaps not surprisingly) that transportation-related variables exert some inßuence on changes to land use patterns, though not as much as variables representing existing and neighboring land uses.Land use, Twin Cities (Minnesota), Mathematical models, urban growth

Location, Regional Accessibility and Price Effects: Evidence from Twin Cities Home Sales

Regional location factors, with measures of regional accessibility foremost among them, exert a strong influence on urban property markets. While accessibility represents an important regional-scale factor, more local influences such as proximity to urban highway links may also positively or negatively influence the desirability of a location. In this paper, we use a cross-section of home sales in Hennepin County, Minnesota from the years 2001 through 2004, along with a set of disaggregate regional accessibility measures, to estimate the value of access to employment and resident workers. We also estimate the (dis)amenity effects of locations near major freeway links that have recently undergone, or were scheduled to undergo (as of the time period covered by the home sales), major construction to add capacity. The richness of the home sales data set allows us to control for a number of structural attributes, as well as some site characteristics, while additional neighborhood characteristics (such as income levels and local educational quality) are added from supplemental data sources. Empirical results indicate that households highly value employment access, while access to other resident workers (i.e. competition for jobs) is considered a disamenity. Proximity to local highway access points is positively associated with sale price, while proximity to the highway link itself is negatively associated with price. The paper concludes with some implications for research and practice of the concept and measurement of the relationship between location and land value.Transportation Ð Economics, Land Value, Accessibility, Hennepin County (MN)

How Local Is Travel?

This paper analyzes the distribution of travel time across different classes of roads for 47 subjects in the Minneapolis-St. Paul metropolitan area. We use global positioning system (GPS) and geographic information system (GIS) data to analyze subject road use, with the objective of getting a sense for how much time individuals spend on different types of roads during their commute trip (in a sense, how ÒlocalizedÓ their travel is). The results reveal an association between the amounts of time spent on various functional classes of roads and home and work locations. Subjects that live and work in the city of Minneapolis are found to spend a higher percentage of their travel time on lower-level (city and county) roads. The results may be used to further inform local road finance decisions in light of the free-rider problem and other problems associated with current financing mechanisms.Travel Behavior; Transportation Ð Finance; Global Positioning Systems (GPS)

Models of Transportation and Land Use Change: A Guide to the Territory

Modern urban regions are highly complex entities. Despite the difficulty of modeling every relevant aspect of an urban region, researchers have produced a rich variety models dealing with inter-related processes of urban change. The most popular types of models have been those dealing with the relationship between transportation network growth and changes in land use and the location of economic activity, embodied in the concept of accessibility. This paper reviews some of the more common frameworks for modeling transportation and land use change, illustrating each with some examples of operational models that have been applied to real-world settings.Transport, land use, models, review network growth, induced demand, induced supply

Value Capture for Transportation Finance

As vehicles become more fuel-efficient and overall levels of travel stagnate in response to increases in fuel prices, conventional sources of revenue for transportation finance such as taxes on motor fuels have been put under increasing pressure. One potential replacement as a source of revenue is a set of policies collectively referred to as value capture policies. In contrast to fuel taxes and other instruments that impose charges on users of transportation networks, value capture policies seek to generate revenue by extracting a portion of the gains in the value of land that result from improvements to transportation networks. In this paper we identify a set of eight policies that contain elements of the value capture approach. These policies include land value taxes, tax increment financing, special assessments, transportation utility fees, development impact fees, negotiated exactions, joint development, and air rights. We evaluate each of the policies according to four criteria: efficiency, equity, sustainability (in terms of revenue adequacy and stability), and feasibility. The value capture concept is placed within a more general framework of transportation finance that emphasizes the relationship between different types of charges and groups of beneficiaries from transportation investments.Transportation Ð Economics, Land value, Transportation Ð finance and taxation

The two-layer skirted island

Author Posting. © Yale University, 2011. This article is posted here by permission of Yale University for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 69 (2011): 347-382, doi:10.1357/002224011798765222.The flow around a planetary scale island in a baroclinic ocean is examined when the island possesses a topographic skirt representing a steep continental slope and the ocean is modeled as a two-layer system in order to examine the role of stratification in the circulation. The study extends an earlier barotropic model of similar geometry and forcing to focus on the degree to which the topography, limited here to the lower of the two layers, affects the circulation and to what degree the circulation is shielded by stratification from the topographic effects noted in the simpler barotropic model. As in the barotropic model, the topography is steep enough to produce closed, ambient potential vorticity contours over the topography in the lower layer providing free "highways" for the deep flow in the presence of small forcing by the wind-driven upper layer flow. The flow is very weak outside the region of closed contours but can become of the same order, if somewhat smaller, as the upper layer flow on those contours in the presence of even weak coupling to the upper layer. A series of models, analytical and numerical, are studied. Linear theory is applied to two configurations. The first consists of a long, meridionally oriented island with a topographic skirt in the lower layer. The lower layer flow is driven by a hypothesized frictional coupling between the two layers that depends on the circulation of the upper layer velocity on a circuit defined by the closed potential vorticity contours of the lower layer. The largest part of the driving flow is identical on both sides of the island and cancels in the contour integration. The major part of the residual forcing comes from relatively small but effective forcing on the semi-circular tips of the topographic skirt. A circular island with a topographic skirt is also examined in which the coupling to the upper layer is stronger all around the island. Even in this case there is a delicate balance of the forcing of the lower layer on each side of the island. In all cases the flow on closed potential vorticity contours in the lower layer is much weaker than in the barotropic model but much stronger than in the flat region of the lower layer. A sequence of numerical calculations that both check and extend the analytic linear theory is presented demonstrating the subtlety of the force balances. Further nonlinear, eddy-containing experiments give a preview of the direction of future work.This research was supported in part by a grant from the National Science Foundation (JP) NSF OCE 0925061 and (MAS) NSF OCE 0926656

The utility of twins in developmental cognitive neuroscience research: How twins strengthen the ABCD research design

The ABCD twin study will elucidate the genetic and environmental contributions to a wide range of mental and physical health outcomes in children, including substance use, brain and behavioral development, and their interrelationship. Comparisons within and between monozygotic and dizygotic twin pairs, further powered by multiple assessments, provide information about genetic and environmental contributions to developmental associations, and enable stronger tests of causal hypotheses, than do comparisons involving unrelated children. Thus a sub-study of 800 pairs of same-sex twins was embedded within the overall Adolescent Brain and Cognitive Development (ABCD) design. The ABCD Twin Hub comprises four leading centers for twin research in Minnesota, Colorado, Virginia, and Missouri. Each site is enrolling 200 twin pairs, as well as singletons. The twins are recruited from registries of all twin births in each State during 2006–2008. Singletons at each site are recruited following the same school-based procedures as the rest of the ABCD study. This paper describes the background and rationale for the ABCD twin study, the ascertainment of twin pairs and implementation strategy at each site, and the details of the proposed analytic strategies to quantify genetic and environmental influences and test hypotheses critical to the aims of the ABCD study. Keywords: Twins, Heritability, Environment, Substance use, Brain structure, Brain functio

Collaborative Research: The Influence of Cloud Microphysics and Radiation on the Response of Water Vapor and Clouds to Climate Change

Uncertainties in representing the atmospheric water cycle are major obstacles to an accurate prediction of future climate. This project focused on addressing some of these uncertainties by implementing new physics for convection and radiation into the NCAR climate model. To better understand and eventually better represent these processes, we modified CAM3.5 to use the convection and cloud schemes developed by the Massachusetts Institute of Technology (MIT) and the RRTMG rapid radiation code for global models developed by Atmospheric and Environmental Research, Inc. (AER). The impact of the new physics on the CAM3.5 simulation of convection on diurnal and intra-seasonal scales, intra-seasonal oscillations and the distribution of water vapor has been investigated. The effect of the MIT and AER physics also has been tested in the Weather Research and Forecasting (WRF) regional forecast model. It has been found that the application of the AER radiation and MIT convection produces significant improvements in the modeled diurnal cycle of convection, especially over land, in the NCAR climate model. However, both the standard CAM3.5 (hereinafter STD) and the modified CAM3.5 with the new physics (hereinafter MOD) are still unable to capture the proper spectrum and propagating characteristics of the intra-seasonal oscillations (ISOs). The new physics methods modify, but do not substantially improve, the distribution of upper tropospheric water vapor relative to satellite measurements

Methods for Estimating the Economic Impacts of Transportation Improvements: An Interpretive Review

This chapter reviews several methods of evaluating the economic impacts of transportation improvements. We begin with a discussion of basic project-based methods, such as benefit- cost analysis, and discuss some issues which may complicate the accurate estimation of user benefits over the life of a project, especially the dynamic and recursive relationship between transportation networks and land development. We discuss the possible role of capitalized land value changes as an alternate source of estimated user benefits. We then move on to a discussion of regional economic analysis models as a tool for examining the effects of large- scale projects or packages of transportation improvements. Their linkages with non-traditional sources of benefits, such as agglomeration effects, and also network effects is considered. Lastly, we consider aggregate analysis methods. These include production function analy- ses, cliometric studies, and other types of empirical investigations of the relationship between transportation and econometric growth at an aggregate scale. We close by commenting on the merits of each approach, and where and how they might usefully be applied