Infrastructure

Bus and Rail Network Design and Exposure to Extreme Heat

We have developed a framework for assessing exposure to environmental conditions (e.g., extreme heat, precipitation, or cold) based on network analyses of parcels, transit networks, and transit schedules. We simulate for every residential parcel in a city how long they are exposed based on their walking times to and from transit and their waiting times at transit. Our results show that, in the case of Southwest U.S. cities, that when temperature is highest (midday), exposure is greatest due to lower headways at offpeak times. We overlay social vulnerability indices to show which neighborhoods are at greatest risk. With this information we are able to direct transit agencies towards strategic investments in schedule changes, public outreach, and communication of transit schedules to reduce these vulnerabilities.

Parking by the Bay: The Supply and Implications of Parking Infrastructure in the San Francisco Bay Area

Journal of Transportation and Land Use, 2022, 15(1), pp. 527-545, doi: 10.5198/jtlu.2022.2123

The San Francisco Bay Area is one of the most progressive transportation regions in the deployment of high-capacity transit and the use of policies to encourage active transportation. Yet, there remains a dearth of knowledge on the abundance and location of parking infrastructure. The extent and location of parking supply, including on-street and off-street spaces, are estimated for the nine-county Bay Area by creating a federated database that joins land use, transportation, parcel, building, and parking code layers to estimate the number and characteristics of parking spaces at the census block scale. This bottom-up parking space inventory results in an estimated 15 million parking spaces in the region: 8.6 million on-street, and 6.4 million off-street. Residential parking dominates the share of supply at 70%, followed by commercial at 9.4%. Space density is greatest in downtown San Francisco, Oakland, and San Jose—largely attributed to high-rise structures. On-street parking is dominant in the North Bay, commanding 78% of total parking in Napa, 75% in Solano, 68% in Sonoma, and 67% in Marin County. Parking area constitutes 7.9% of the total incorporated area. Notably, when compared to other southwest cities (Phoenix Metropolitan Area and Los Angeles County), the Bay Area parking supply appears better utilized considering spaces per person, per car, and per job. The density and quantity of parking spaces in the Bay Area are critical insights towards developing targeted policies that encourage active mobility and support affordable housing.

Urban Heat Implications from Parking, Roads, and Cars: A Case Study of Metro Phoenix

Sustainable and Resilient Infrastructure, 2022, 7(4), pp. 272-290, doi: 10.1080/23789689.2020.1773013

Urban heat is a growing concern in cities as a consequence of persisting urbanization exacerbated by climate change. To help understand how city planning and the transportation sector can influence and mitigate heat in cities, this research quantifies contributions to urban heat from pavement infrastructure and vehicle travel. A case study of metropolitan Phoenix, Arizona is chosen for its rapid growth, hot climate, and high automobile dependence. A one-dimensional model based on fundamental heat transfer is developed and validated using remotely sensed land surface temperatures for scenarios of local weather and pavement design. Simulated sensible heat emissions from pavements are applied to a regional roadway and parking pavement inventory and combined with road-level vehicle travel densities to quantify spatiotemporal sensible heat flux magnitudes. In metro Phoenix, total sensible heat from pavements and vehicles is comprised of 67% from roadway pavements, 29% from parking pavements, and 3.9% vehicles. Under typical Phoenix conditions, concrete and asphalt pavements emit an average of 15% and 37% more sensible heat compared to the bare ground, respectively. This added sensible heat from pavement infrastructure peaks during summer afternoons when heat emissions relative to the ground can increase to 26% for concrete and 46% for asphalt. These results indicate pavement infrastructure contributes significantly to Phoenix’s urban heat balance, and areas surrounding high capacity vehicle corridors may be undesirable for outdoor travel or activities during summer rush hours. Future research quantifying urban heat fluxes should consider quantifying added heat from pavement infrastructure in addition to traditional anthropogenic sources.

Valley of the Sun-Drenched Parking Space

Transfers Magazine, 2020

Most cities have little to no idea how many parking spaces they have. Nevertheless, we know that most cities have a lot of parking, and that most of it is free. This free parking comes with significant economic, environmental, and social costs. A city full of parking is a city designed for cars. When cities are designed for cars, car use becomes necessary, which makes drivers call for more car-oriented design, even though such design leads to more driving and pollution, and creates landscapes that hinder walking, biking and transit use.

Using Social Media to Evaluate Associations Between Parking Supply and Parking Sentiment

Transportation Research Interdiscplinary Perspectives, 2020, 4(100085), doi: 10.1016/j.trip.2019.100085

A common complaint against changing parking requirements is that parking is critical for businesses to survive. Such statements are generally taken as a statement of fact by planners and local officials, yet there is little empirical work in support of this claim. This research examines how online business reviews reflect customer sentiment toward parking, and how this sentiment is associated with the supply of parking. The Phoenix, Arizona region is used for this analysis. The parking supply at the parcel level is combined with data from user-generated Yelp business reviews to assess satisfaction or frustration with parking at different types of businesses in commercial districts across the region. Results suggest that parking is mentioned in about 5% of overall reviews, and when mentioned in reviews it is most often as a negative characteristic of the establishment. Reviews that mention parking also give significantly lower ratings to businesses. The analysis shows that parking sentiment may be associated in some cases with parking supply, e.g. districts with more parking spaces per business tend to have more positive parking sentiment. Additionally, in areas with shared parking facilities, parking was generally viewed more positively or mentioned less frequently. These findings suggest that parking supply is part of a customer's overall perception of a business, though not a major component, and that shared parking facilities are not associated with negative reviews. Implications for policy are that shared parking can be part of an overall package of parking reforms that satisfy businesses and customers alike.

Valley of the Sun-drenched Parking Space: The Growth, Extent, and Implications of Parking Infrastructure in Phoenix

Cities, 2019, 89, pp. 186-198, doi: 10.1016/j.cities.2019.02.007

There is little knowledge of how much parking infrastructure exists in cities despite mounting evidence that abundant and underpriced parking creates economic, environmental, and social problems. Urban parking requirements are very precise and routinely enforced despite the fact that most cities have little to no knowledge about their own parking supply. To further explore these issues, a parking inventory for metropolitan Phoenix, Arizona, USA is developed by cross-referencing geospatial cadastral and roadway data with minimum parking requirements. Metropolitan Phoenix is chosen because it is relatively young, rapidly growing, highly sprawled, and car dependent. Historical growth of parking is also estimated by linking year of property development to required off-street and nearby on-street parking spaces. As of 2017, we estimate that there are 12.2 million parking spaces in the metropolitan region with 4.04 million inhabitants, 2.81 million registered personal vehicles, and 1.84 million jobs. Growth of parking in metro Phoenix has also been significant; since 1960, 10.9 million spaces have been added to the region compared to a population growth of 3.41 million, vehicle fleet growth of 2.63 million, and employment growth of 1.56 million. Since the 2008 recession, parking growth in metro Phoenix has significantly slowed, but continued urban growth combined with substantial minimum parking requirements may promote more parking infrastructure than is needed. Planners and policy makers should value quantifying the growth and supply of parking in urban areas and consider reforming parking standards to promote consistent and unambiguous pathways to sustainable urban growth.

Heat Exposure and Transit Use: Travel Behavior and Infrastructure

ASU Report No. ASU-SSEBE-CESEM-2017-CPR-001

Public transit necessitates environmental exposure and there is increasing recognition that in a future with hotter temperatures new strategies are needed to protect passengers. Arizona State University’s Spring 2017 Urban Infrastructure Anatomy course assessed travel behavior, public transit stop design, and heat exposure to develop recommendations for mitigating heat exposure. Travel surveys, analysis of infrastructure characteristics, and thermal imaging were used to assess exposure. A suite of mitigation strategies was developed from a literature review, conversations with experts, and review of other transit systems. Focusing on neighborhoods in Tempe, Arizona, strategies are developed for protecting future riders from negative health outcomes.

The Net Greenhouse Gas Impact of the Sheppard Subway Line

Transportation Research Part D: Transport and Environment, 2017, 51, 261-275, doi: 10.1016/j.trd.2017.01.007

As cities work to reduce their total greenhouse gas (GHG) emissions, the transportation sector is lagging, accounting for a growing percentage of total emissions in many cities. The provision of public transit, and specifically urban rail transit, is widely seen as a useful tool for reducing urban transportation GHG emissions. There is, however, limited understanding of the net impact of new metro rail infrastructure on urban emissions. This paper examines the net GHG emission of the Sheppard Subway Line in Toronto, Canada. The GHG emissions associated with construction, operation, ridership and changes in residential density associated with the provision of the new metro rail infrastructure are assessed. These components are then combined and compared to calculate the net GHG impact across the study period, which extends from opening in 2002 through 2011. The GHG payback period is calculated. After nine years of operation, the Sheppard Subway Line is found to have nearly paid back its initial GHG investment in the optimistic case. The payback was due to the calculated mode shift from automobiles, changes in residential density and associated energy savings in the station pedestrian catchment areas. The payback period is very sensitive to the potential for induced demand to backfill the mode shifted automobile kilometres.

Environmental and Economic Consequences of Permanent Roadway Infrastructure Commitment: City Road Network Life-cycle Assessment and Los Angeles County

ASCE Journal of Infrastructure Systems, 2016, 22(1), doi: 10.1061/(ASCE)IS.1943-555X.0000271

The environmental impacts and economic costs associated with passenger transportation are the result of complex interactions between people, infrastructure, urban form, and underlying activities. When it comes to roadway infrastructure, the ongoing resource commitments (which can be measured as embedded impacts) enables vehicle travel, which is a dominant source of air emissions in regional inventories. The relationship between infrastructure and the environmental impacts it enables are not often considered dynamic. Furthermore, the environmental effects of roadway infrastructure are typically assessed at a fine geospatial and temporal scale (i.e., a short distance of roadway over a short period of time) and there is generally poor knowledge of how the growth of a roadway network over time creates a need for long-term maintenance commitments that create environmental impacts and lock-in vehicle travel. A framework and operational lifecycle assessment (LCA) tool [City Road Network (CiRN) LCA] are developed to assess the extent to which roadway commitments result in ongoing and increasing environmental and economic impacts. Known for its extensive road network and automobile reliance, Los Angeles County is used as a case study to explore the relationship between historic infrastructure deployment decisions and the emergent behavior of vehicle travel. The results show that every kilogram of greenhouse gas (GHG) emissions resulting from construction and maintenance has led to 27 kg of GHG emissions in fuel combustion. Similarly, every public dollar invested into the network has created $21–$46 in private user spending. As states and regions grapple with financing the upkeep of aging infrastructure, a solid understanding of the relationship between upfront infrastructure capital costs, long-term maintenance costs, and associated long-term environmental effects are critical. In Los Angeles, the infrastructure that exists was largely deployed by 1987. Since then, maintenance costs are estimated to have exceeded city budgets despite minimal growth in infrastructure. The research demonstrates how infrastructure matures (i.e., its stages of growth toward completion), it becomes locked-in, leading to transitions from a capital financing focus to foci on securing rehabilitation and maintenance costs, and the share of environmental impacts changing from being somewhat balanced between embedded infrastructure construction impacts and vehicle use to today where vehicle use creates impacts several orders of magnitude greater than those associated with rehabilitation.

Parking Infrastructure: A Constraint on or Opportunity for Urban Redevelopment? A Study of Los Angeles County Parking Supply and Growth

Journal of the American Planning Association, 2015, 81(4), pp. 268-286 doi: 10.1080/01944363.2015.1092879

Many cities have adopted minimum parking requirements but we have relatively poor information about how parking infrastructure has grown. We estimate how parking has grown in Los Angeles County from 1900 to 2010 and how parking infrastructure evolves, affects urban form, and relates to changes in automobile travel, using building and roadway growth models. We find that since 1975 the ratio of residential offstreet parking spaces to automobiles in Los Angeles County is close to 1.0 and the greatest density of parking spaces is in the urban core while most new growth in parking occurs outside of the core. 14% of incorporated land in Los Angeles County is committed to parking. Uncertainty in our space inventory is attributed to our building growth model, onstreet space length, and the assumption that parking spaces were created as per the requirements. The continued use of minimum parking requirements is likely to encourage automobile use at a time when metropolitan areas are actively seeking to manage congestion and increase transit use, biking, and walking. Widely discussed ways to reform parking policies may be less than effective if planners do not consider the remaining incentives to auto use created by the existing parking infrastructure. Planners should encourage the conversion of existing parking facilities to alternative uses.

Cost-effectiveness of Reductions in Greenhouse Gas Emissions from High-speed Rail and Urban Transportation Projects in California

Transportation Research Part D, 2015, 40, pp. 104-113, doi: 10.1016/j.trd.2015.08.008

As California establishes its greenhouse gas emissions cap-and-trade program and considers options for using the new revenues produced under the program, the public and decision-makers have access to tenuous information on the relative cost-effectiveness of passenger transportation investment options. Towards closing this knowledge gap, the cost-effectiveness of greenhouse gas reductions forecast from High-Speed Rail are compared with those estimated from recent urban transportation projects (specifically light rail, bus rapid transit, and a bicycling/pedestrian pathway) in California. Life-cycle greenhouse gas emissions are joined with full cost accounting to better understand the benefits of cap-and-trade investments. Results are largely dependent on the economic cost allocation method used. Considering only public subsidy for capital, none of the projects appear to be a cost-effective means to reduce greenhouse gas emissions (i.e., relative to the current price of greenhouse gas emissions in California’s cap-and-trade program at $11.50 per tonne). However, after adjusting for the change in private costs users incur when switching from the counterfactual mode (automobile or aircraft) to the mode enabled by the project, all investments appear to reduce greenhouse gas emissions at a net savings to the public. Policy and decision-makers who consider only the capital cost of new transportation projects can be expected to incorrectly assess alternatives and indirect benefits (i.e., how travelers adapt to the new mass transit alternative) should be included in decision-making processes.

Automobile Path Dependence in Phoenix: Driving Sustainability by Getting Off of the Pavement and Out of the Car

Arizona State University Doctoral Dissertation

A methodology is developed that integrates institutional analysis with Life Cycle Assessment (LCA) to identify and overcome barriers to sustainability transitions and to bridge the gap between environmental practitioners and decisionmakers. LCA results are rarely joined with analyses of the social systems that control or influence decisionmaking and policies. As a result, LCA conclusions generally lack information about who or what controls different parts of the system, where and when the processes' environmental decisionmaking happens, and what aspects of the system (i.e. a policy or regulatory requirement) would have to change to enable lower environmental impact futures. The value of the combined institutional analysis and LCA (the IA-LCA) is demonstrated using a case study of passenger transportation in the Phoenix, Arizona metropolitan area. A retrospective LCA is developed to estimate how roadway investment has enabled personal vehicle travel and its associated energy, environmental, and economic effects. Using regional travel forecasts, a prospective life cycle inventory is developed. Alternative trajectories are modeled to reveal future "savings" from reduced roadway construction and vehicle travel. An institutional analysis matches the LCA results with the specific institutions, players, and policies that should be targeted to enable transitions to these alternative futures. The results show that energy, economic, and environmental benefits from changes in passenger transportation systems are possible, but vary significantly depending on the timing of the interventions. Transition strategies aimed at the most optimistic benefits should include 1) significant land-use planning initiatives at the local and regional level to incentivize transit-oriented development infill and urban densification, 2) changes to state or federal gasoline taxes, 3) enacting a price on carbon, and 4) nearly doubling vehicle fuel efficiency together with greater market penetration of alternative fuel vehicles. This aggressive trajectory could decrease the 2050 energy consumption to 1995 levels, greenhouse gas emissions to 1995, particulate emissions to 2006, and smog-forming emissions to 1972. The potential benefits and costs are both private and public, and the results vary when transition strategies are applied in different spatial and temporal patterns.

Growth of the Los Angeles Roadway Network

A project to assess the growth of transportation infrastructure in Los Angeles and its drivers

We model the deployment of roadway infrastructure in Los Angeles County. Presented below is an animation of the deployment of the Los Angeles Roadway network, from 1990 to present. The work is published: A Fraser and M Chester, Environmental and Economic Consequences of Permanent Roadway Infrastructure Commitment: City Road Network Life-cycle Assessment and Los Angeles County, ASCE Journal of Infrastructure Systems, 2016, 22(1), doi: 10.1061/(ASCE)IS.1943-555X.0000271.

Growth of the Phoenix Roadway Network

A project to assess the growth of transportation infrastructure in Phoenix and its drivers

The growth of the Phoenix roadway network developed through a combined roadway link and travel analysis zone statistical assessment of building ages. Infrastructure has been constructed ahead of and in concert with sprawling edge growth. Half of the current roadways were constructed after 1979 at the edges of the urbanized area (i.e., the 101, 202, and 303 loops).

Life-cycle Assessment for Construction of Sustainable Infrastructure

ASCE Practice Periodical on Structural Design and Construction, 2014, 19(1), 89-94, doi: 10.1061/(ASCE)SC.1943-5576.0000187

The architecture-engineering-construction (AEC) industry faces increasing demands on its projects while budgets appear to be shrinking. Building owners and operators seem to want their buildings to do more for less cost. Although this may seem counterintuitive, it aligns nicely with a sustainable-architecture approach of less is more. Moreover, in a shift from exclusively considering first costs for a project, the AEC industry seems to be moving in the direction of life-cycle cost considerations, furthering the opportunity for a more sustainable built environment. Often sustainable is synonymous with achieving certification [e.g., Leadership in Energy and Environmental Design (LEED) and Infrastructure Voluntary Evaluation Sustainability Tool (INVEST) certification]. Whereas the authors acknowledge that certification can improve particular aspects of sustainability, it is necessary to take a broader approach and consider economic, environmental, and social dimensions of sustainability. In this paper, the authors explore each of these dimensions and present examples of how the AEC industry can measure, balance, and monetize them.

Infrastructure and Automobile Shifts: Positioning Transit to Reduce Life-cycle Environmental Impacts for Urban Sustainability Goals

Environmental Research Letters, 2013, 8(1), 015041, doi: 10.1088/1748-9326/8/1/015041

Public transportation systems are often part of strategies to reduce urban environmental impacts from passenger transportation yet comprehensive energy and environmental life-cycle measures, including upfront infrastructure effects and indirect and supply chain processes, are rarely considered. Using the new bus rapid transit and light rail lines in Los Angeles, near-term and long-term life-cycle impact assessments are developed, including reduced automobile travel. Energy consumption and emissions of greenhouse gases and criteria pollutants are assessed, as well the potential for smog and respiratory impacts. Results show that life-cycle infrastructure, vehicle, and energy production components significantly increase the footprint of each mode (by 48-100% for energy and greenhouse gases, and up to 6200% for environmental impacts), and emerging technologies and renewable electricity standards will significantly reduce impacts. Life-cycle results are identified as either local (in Los Angeles) or remote and show how the decision to build and operate a transit system in a city produces environmental impacts far outside of geopolitical boundaries. Ensuring shifts of between 20-30% of transit riders from automobiles will result in passenger transportation greenhouse gas reductions for the city, and the larger the shift the quicker the payback, which should be considered for time-specific environmental goals.

Parking Infrastructure and the Environment

Access Magazine 39, Fall 2011

California is planning to spend $40 billion to build a high speed rail system from San Diego to Sacramento. Advocates argue that high speed rail will save money and improve the environment, while critics claim it will waste money and harm the environment. What accounts for these diametrically opposed views about a technology that has been operating in other countries for decades? And what can transportation analysts offer to inform the debate? Disagreements about the cost and environmental impacts of high speed rail can arise when analysts examine only the most direct effects of the rail system, and compare those to only the direct effects of road and air travel—-the two transportation modes from which high speed rail will likely draw passengers. But transportation energy use and emissions result not only from the direct effects of operating the vehicles but also from indirect effects, such as building the infrastructure, producing the fuels, manufacturing the vehicles, maintaining the system, and disposing of materials at the end of their lives. The full range of emissions from automobile travel, for example, includes not only tailpipe emissions but also the emissions created by building roads and parking garages, manufacturing cars, extracting and refining petroleum, and, finally, wrecking yards and tire dumps. One approach to environmental and cost-benefit analysis that takes both these direct and indirect effects into account is life-cycle assessment. In this article we use life-cycle assessment to compare the energy use and pollution emissions of high speed rail and its competing modes.

Parking Infrastructure: Energy, Emissions, and Automobile Life-cycle Environmental Accounting

Environmental Research Letters, 2010, 5(3), doi: 10.1088/1748-9326/5/3/034001

The US parking infrastructure is vast and little is known about its scale and environmental impacts. The few parking space inventories that exist are typically regionalized and no known environmental assessment has been performed to determine the energy and emissions from providing this infrastructure. A better understanding of the scale of US parking is necessary to properly value the total costs of automobile travel. Energy and emissions from constructing and maintaining the parking infrastructure should be considered when assessing the total human health and environmental impacts of vehicle travel. We develop five parking space inventory scenarios and from these estimate the range of infrastructure provided in the US to be between 105 million and 2 billion spaces. Using these estimates, a life-cycle environmental inventory is performed to capture the energy consumption and emissions of greenhouse gases, CO, SO2, NOX, VOC (volatile organic compounds), and PM10 (PM: particulate matter) from raw material extraction, transport, asphalt and concrete production, and placement (including direct, indirect, and supply chain processes) of space construction and maintenance. The environmental assessment is then evaluated within the life-cycle performance of sedans, SUVs (sports utility vehicles), and pickups. Depending on the scenario and vehicle type, the inclusion of parking within the overall life-cycle inventory increases energy consumption from 3.1 to 4.8 MJ by 0.1–0.3 MJ and greenhouse gas emissions from 230 to 380 g CO2e by 6–23 g CO2e per passenger kilometer traveled. Life-cycle automobile SO2 and PM10 emissions show some of the largest increases, by as much as 24% and 89% from the baseline inventory. The environmental consequences of providing the parking spaces are discussed as well as the uncertainty in allocating paved area between parking and roadways.

Environmental Assessment of Passenger Transportation Should Include Infrastructure and Supply Chains

Environmental Research Letters, 2009, 4(2), doi: 10.1088/1748-9326/4/2/024008

To appropriately mitigate environmental impacts from transportation, it is necessary for decision makers to consider the life-cycle energy use and emissions. Most current decision-making relies on analysis at the tailpipe, ignoring vehicle production, infrastructure provision, and fuel production required for support. We present results of a comprehensive life-cycle energy, greenhouse gas emissions, and selected criteria air pollutant emissions inventory for automobiles, buses, trains, and airplanes in the US, including vehicles, infrastructure, fuel production, and supply chains. We find that total life-cycle energy inputs and greenhouse gas emissions contribute an additional 63% for onroad, 155% for rail, and 31% for air systems over vehicle tailpipe operation. Inventorying criteria air pollutants shows that vehicle non-operational components often dominate total emissions. Life-cycle criteria air pollutant emissions are between 1.1 and 800 times larger than vehicle operation. Ranges in passenger occupancy can easily change the relative performance of modes.