Sustainability Tools in Action

Cities affect and are affected by climate change. Local land use comprehensive plans have an essential role in greenhouse gas (GHG) emission reduction. The study addresses two critical research questions: 1) How well do the fastest growing cities in the U.S. implement the low-carbon principles in their local comprehensive land use plans? and 2) How can local comprehensive land use plans be improved to promote low-carbon development? An evaluation protocol with five plan components and thirty-five indicators was developed to measure local land use planning capacity in building low-carbon cities. Results show that the majority of these cities have already established their comprehensive low-carbon city framework; however, they fail to fully incorporate specific low-carbon planning strategies into their plans. These cities can improve their local plan quality by enhancing the scientific basis of the plans, adopting more specific goals and policies, and expanding the planners' toolbox to achieve low-carbon city planning.

Land use policy is viewed as a way to mitigate congestion and alleviate greenhouse gas emissions. Many studies have confirmed the reduction effect for vehicle miles traveled (VMT) of compact and mixed land use development. However, debates on self-selection effects have arisen in recent years. Researchers argue that the correlation between land use pattern and VMT may be caused by self-selection of residential location based on a person's attitude toward traveling. This paper develops an urban form indicator for describing local land use patterns and then establishes a structural equation model (SEM) with VMT, vehicle ownership, and the urban form of residential location estimated simultaneously. Residential self-selection was controlled in two ways in the model: implicitly through the correlated error terms in multiple equations and explicitly through the incorporation of expected VMT in the equation of residential location choice. The model was estimated with household travel survey data collected in 2007 in the Washington, D.C., area. The results showed that land use itself could influence travel behavior after self-selection effects were removed. A comparison of the results of the full SEM results with that of a reference SEM confirmed the existence of self-selection effects. The comparison verified that the VMT reduction effect of land use would be exaggerated without consideration of self-selection, and self-selection effect accounted for a larger part of the total effect in more compact and better mixed development areas. However, the self-selection effect was small compared with the effect of land use itself in the analyzed case.

Problem: Congestion pricing and land use planning have been proposed as two promising strategies to reduce the externalities associated with driving, including traffic congestion, air pollution, and greenhouse gas emissions. However, they are often viewed by their proponents as substitutive instead of complementary to each other. Purpose: Using data from a pilot mileage fee program run in Portland, OR, we explored whether congestion pricing and land use planning were mutually supportive in terms of vehicle miles traveled (VMT) reduction. We examined whether effective land use planning could reinforce the benefit of congestion pricing, and whether congestion pricing could strengthen the role of land use planning in encouraging travelers to reduce driving. Methods: VMT data were collected over 10 months from 130 households, which were divided into two groups: those who paid a mileage charge with rates that varied by congestion level (i.e., congestion pricing) and those who paid a mileage charge with a flat structure. Using regression models to compare the two groups, we tested the effect of congestion pricing on VMT reduction across different land use patterns, and the effect of land use on VMT reduction with and without congestion pricing. Results and conclusions: With congestion pricing, the VMT reduction is greater in traditional (dense and mixed-use) neighborhoods than in suburban (single-use, low-density) neighborhoods, probably because of the availability of travel alternatives in the former. Under the same land use pattern, land use attributes explain more variance of household VMT when congestion pricing is implemented, suggesting that this form of mileage fee could make land use planning a more effective mechanism to reduce VMT. In summary, land use planning and congestion pricing appear to be mutually supportive. Takeaway for practice: For policymakers considering mileage pricing, land use planning affects not only the economic viability but also the political feasibility of a pricing scheme. For urban planners, congestion pricing provides both opportunities and challenges to crafting land use policies that will reduce VMT. For example, a pricing zone that overlaps with dense, mixed-use and transit-accessible development, can reinforce the benefits of these development patterns and encourage greater behavioral changes. Research support: This project was supported by the Mineta Transportation Institute, where the authors are research associates.

Historically, the State of California assessed the environmental impacts of proposed developments based on how it was projected to affect an area’s level of service (LOS). However, as LOS focused on traffic delays, many agencies simply widened roads, which was an ineffective way to reduce greenhouse gas emissions (GHGs). With the passage of Senate Bill (SB)743 in 2013, LOS was replaced by Vehicle Miles Traveled (VMT) as a more appropriate metric by which to gauge the environmental impacts of proposed development. Additionally, SB 743 presented an opportunity for off-site VMT mitigation strategies through banking and exchanges– allowing multiple development projects to fund a variety of strategies to reduce VMT elsewhere in the city or region. While the shift from LOS to VMT has generally been lauded, concerns remain about how to apply SB 743 effectively and equitably. This study aimed to: 1) understand how local governments are addressing this shift toward VMT while ensuring equity, including its approaches to off-site VMT mitigation; and 2) evaluate the various built environment factors that impact VMT, which should be considered by local governments, using both qualitative and quantitative research designs. The study posited that both micro and macro level aspects of the built environment needed to be considered when evaluating the impacts of proposed development on VMT, not only to ensure higher accuracy VMT models, but also because of the potential equity implications of off-site mitigation measures. Using multiple linear regression, the study shows that macroscale built environment features such as land use, density, housing, and employment access have a statistically significant impact on reducing VMT (35%), along with transit access (15%), microscale features such as sidewalks, benches, and trees (13%), and income (6%). More notably, a four-way interaction was detected, indicating that VMT is dependent on the combination of macro and micro level built environment features, public transit access, and income. Additionally, qualitative interviews indicate that transportation practitioners deal with three types of challenges in the transition to VMT impact mitigation: the lack of reliable, standardized VMT measure and evaluation tools; the lack of a strong legal foundation for VMT as a component of the California Environmental Quality Act (CEQA); and the challenge of distributing off-site VMT mitigation equitably. Overall, findings support a nuanced, multi-factor understanding of the context in which new developments are being proposed, both in terms of modeling VMT, but also when considering whether offsite mitigation would be appropriate. The results of this study can help California ensure equitable VMT mitigation that better aligns with the state’s climate goals.

Bi-level optimization approach for configuring population and employment distributions with minimized vehicle travel demand

“Planning for Transit-Supportive Development: A Practitioner’s Guide” is a toolkit of practical and innovative measures to help Metropolitan Planning Organizations (MPOs), regional planners, transit agencies, and local government elected officials, staff, land use planners, and transit planners integrate transit planning with local land use planning. This guide includes best practices, guidance, success stories, useful techniques, transferable examples, and lessons learned, aimed at providing planners at the regional, corridor, and local levels with ideas on how to integrate, accommodate, and assess transit-supportive development and transit investment. Included are numerous success stories for integrating transit planning and land use planning. This guide seeks to go beyond just highlighting case studies by providing a link between the regional, corridor, and local planning processes for integrating land use and transit and examining regions that have successfully developed and integrated plans. The guide is meant to be a resource for planners to assist them in the development and implementation of strategies to integrate transit and land use planning in an effort to encourage transit-supportive development. “Section 3: Regional Vision Planning and Transit-Supportive Development” presents key ingredients for developing regional vision plans and methods for forecasting regional markets.

Are we successful in reducing vehicle miles traveled in air quality nonattainment areas?

While voluminous empirical studies have examined the impact of land use on travel behavior, few have relied on longitudinal data and an analytical approach. With data from two activity travel surveys (1997 and 2006) conducted in Austin, Texas, this paper develops a longitudinal multilevel model for estimating the change in the effect of land use on vehicle miles of travel (VMT) over time and the long-range land use effect on VMT reduction. Results suggest that the influences of land use mixture and street density on VMT would vary between 2 years. The effects of VMT reduction on land use policies by raising population and street densities are salient in the short run but insignificant in the long run, whereas those of mixed-use policies are even larger in the long run. These findings validate the importance of longitudinal data and analysis in land use–travel studies and suggest that the short-run elasticity of land use derived from cross-sectional analyses may be inappropriate for assessing the long-run effect of land use–based mobility strategies for reducing VMT.

Transportation and land use research of the past decade has focused in large part on the question of whether manipulating land uses in the direction of “smart growth” alternatives can reduce vehicle miles traveled (VMT) or otherwise improve travel behavior. Yet the notion of “manipulating” land uses implies that the alternative is somehow self-organized or market-based. This view appears to underestimate the extent to which current planning interventions in the United States – largely focused on lowering development densities, mandating ample road and parking designs, and separating land uses – impose an auto-oriented template on most new development. Rather than a market failure, the paucity of “smart growth” alternatives may be a planning failure – the result of municipal regulatory exclusion. This problem definition would shift the burden of proof for policy reform, as uncertainty in travel-behavior benefits would hardly justify the continuation of exclusionary regulations. If municipal regulations in fact constrain alternatives to low-density, auto-oriented development, one would expect developers to perceive unsatisfied market interest in such development. This article studies, through a national survey (676 respondents), US developers' perceptions of the market for pedestrian-and transit-oriented development forms. Overall, respondents perceive considerable market interest in alternative development forms, but believe that there is inadequate supply of such alternatives relative to market demand. Developer-respondents attribute this gap between supply and demand principally to local government regulation. When asked how the relaxation of these regulations would affect their product, majorities of developers indicated that such liberalization would lead them to develop in a denser and more mixed-use fashion, particularly in close-in suburban locales. Results are interpreted in favor land-policy reform based on the expansion of choice in transportation and land use. This view contrasts with a more prevalent approach which conditions policy interventions on scientific evidence of travel-behavior modification.

An integrated land-use�transportation model was used to simulate the impact that an urban growth boundary would have on vehicle miles of travel in a small metropolitan community over a forty-year modeling horizon. The results of the modeling effort indicate that even in an area with low to moderate population growth, there is the potential to reduce vehicle miles of travel per person by as much as 25% from a business-as-usual scenario over a forty-year period. The reduction would result primarily from a shift of driving alone to carpooling or walking for many trips. A scenario in which growth is concentrated in a single urban core would also benefit from shorter average trip lengths; a scenario with multiple village centers would not have shorter trip lengths, but would still have significant improvements in total vehicle miles of travel.

Research has established a potential to reduce vehicle miles traveled (VMT) by replacing passenger travel for shopping with delivery service, and a few studies have indicated CO2 emissions can also be reduced. However, that research has mostly focused on urban locations and has not addressed criteria pollutants. This study examines the impacts of replacing passenger travel for shopping with delivery service over a broader set of externalities (VMT, CO2, NOx, and PM10) in both urban and rural communities. Three different goods movement strategies are considered in three different municipalities in King County, Washington, which vary in size, density, and distance from the metropolitan core. The research finds that delivery services can reduce VMT over passenger vehicle travel for shopping, however, the potential to reduce CO2, NOx, and PM10 emissions varies by municipality. Significant trade-offs are observed between VMT and emissions – especially between VMT and criteria pollutants.

Problem: Market mechanisms are emerging as means of offsetting the environmental effects of growth. Unfortunately, formal regulation of ecosystem markets is often separated from broader planning for urban development, resulting in offsets that are unsustainable in the face of future urban growth. Purpose: We aimed to assess how 2008 federal regulations that actively promote aquatic resource markets and encourage watershed planning to restore wetlands and streams damaged during development will affect reputedly efficient existing wetland and stream ecosystem markets in North Carolina. We explore how coordination between regulators and planners can improve long-term viability of market-created resource offsets and improve the ability of markets to respond to rapid urban growth. Methods: We analyzed new state and federal regulations and watershed planning efforts and convened a stakeholder forum including representatives of state and federal agencies, land developers, environmental groups, aquatic restoration companies, and academia. Results and conclusions: Problems with aquatic ecosystem markets in North Carolina stem from poor communication among local and regional planners, federal regulators, and state agencies. Institutional barriers and poor coordination cause federal regulatory decisions made without knowledge of land use plans or urban development patterns, faulty projections of market demand for aquatic offsets, and local land use plans that do not provide long-term protection for the offsets. Although regulators consider current surrounding land uses, they do not consider future land uses. We conclude that local land use projections should be required components of ecosystem restoration site plans and that state environmental management agencies' watershed plans should reflect urban development patterns. Takeaway for practice: Local planners should have input into the design of restoration sites providing environmental offsets as well as into state and regional ecosystem service market implementation plans. Federal, state, regional, and local agencies should facilitate and require information sharing, making planning and regulating ecosystem service markets part of the development process. Research support: This research was supported by the University of North Carolina's Institute for the Environment.

Rapid development of Connected and Automated Vehicles (CAVs) besides the urgency of cutting down carbon emissions in the next three decades raise a question about the impact of CAVs deployment on carbon emissions from transport sector. The uncertainties around this question are grave due to the complex interactions between technological capabilities, policy interventions and public travel behaviour. Previous modelling and simulation studies suggest a wide variation in how CAVs may contribute to carbon saving strategies or worsen CO2 emissions. This indicates a necessity for breaking the technology down into the mechanisms as well as features that directly or indirectly affect emissions at vehicular and/or network levels. This paper aims to investigate the mechanisms and different ways that CAVs may decrease or increase road carbon emissions in order to constrain the uncertainties. A semi-systematic literature review was designed and conducted which resulted in identification of 40 relevant publications and documents. Subsequently, 38 levers were ascertained and classified across five major categories: i) emissions per mile; ii) emissions per vehicle; iii) emissions from infrastructure; iv) vehicle miles travelled (VMT); and v) emissions per manufactured vehicle. The estimates for potential impacts of the most significant levers on key performance indicators (KPIs) such as VMT, vehicle occupancy rate and number of manufactured vehicles are provided. Some of the plausible policy interventions are discussed. The findings are also closely related to energy consumption (other than carbon emissions). Therefore, the results can be used for studying potential implications for mass adoption of automated and electric vehicles (AEVs).

Mainstreaming climate change adaptation (CCA) links adaptation and sustainable development goals by integrating climate change information, concerns, and considerations into existing development planning, policy- and decision-making processes. It is gaining popularity in developing countries, but its operationalization has been slow because of the challenges that hinder its on-ground application. To understand the nature of these challenges, this paper developed a four-stage mixed methodology that examined mainstreaming of CCA into local land use planning in Albay, Philippines. The methodology includes a modified Institutional Analysis and Development framework for the qualitative analysis, and 20 mainstreaming indicators for the quantitative assessment. The data used in the analysis were collected from a survey and the interviews conducted among the key players in local land use planning in Albay. The correlation analysis showed that the challenges related to knowledge and awareness, local government prioritization, institutional incentives, availability of funds, access to funds, and stability of funds had the highest frequency of interconnections with the other challenges. Also, a strong tripartite relationship among local leadership, local government prioritization, and local government’s commitment to CCA was observed. The paper suggests that mainstreaming challenges are interconnected at varying degrees. It presents analytical tools and quantifiable measures that can be used to develop a reliable basis for the qualitative assessments of adaptation needs and effectiveness. These sets of information can help analyst and practitioners make informed decisions regarding the operationalization of mainstreaming CCA.

The effects of traffic congestion on travel behavior are complex and multidimensional because they are related to various factors such as density, land use patterns, network connectivity, and individual preferences. Traffic congestion is a phenomenon that not only affects transportation systems but also influences commuters’ quality of life and population mobility. The present research aims to analyze the effects of traffic congestion on individuals’ travel behaviors, addressing both direct and indirect effects of congestion on vehicle miles traveled (VMT) per driver by implementing structural equation modeling (SEM) techniques. In addition to the causal analysis between traffic congestion and VMT, this study examined the complex relationship between an individual’s socioeconomic characteristics, the built environment, congestion, and VMT. Measuring local congestion at a national level is also a key contribution of this research. This study used the same methodology as the Texas A&M Transportation Institute to compute a road congestion index and quantify local congestion for 93,769 drivers within 337 metropolitan areas. Our findings suggest that congestion is the main driver of VMT reduction. The findings also confirm that residents in compact development regions have lower daily VMTs because of the proximity of origins and destinations in denser areas with higher job–population balances. Therefore, rather than expanding highway networks, public transit investment might address traffic congestion more efficiently—not only by providing residents with more equitable and sustainable means of transportation, but also by encouraging people to reside in more compact and location-efficient areas.