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• We investigate the environmental benefits of ridesharing and rebound effects. • We use an integrated transport land-use model calibrated to the Paris region. • By reducing the cost of car and congestion, ridesharing yields rebound effects.... • ...that mitigate by about 2/3 initial decreases in CO 2 emissions, mostly due to modal shift. • Road pricing and reducing road capacity can efficiently reduce the rebound effect. This paper investigates how and to what extent changes in user behavior may mitigate the environmental benefits of urban ridesharing, a phenomenon commonly referred to as "rebound effect". Ridesharing reduces both the individual cost of car travel (through cost splitting) and road travel times (by decreasing congestion). This may trigger a number of behavioral changes among transportation users, including: making less detours to avoid congestion (route choice effect), switching from public transit and active modes to the car (modal shift effect), travelling longer distances (distance effect), and relocating further from the urban center (relocation effect). Taking Paris region as a case study, this research applies an integrated transportation/land-use model to evaluate several ridesharing scenarios and quantify the four rebound effects. The overall rebound effect is found to be substantial, cancelling out from 68 to 77% of CO 2 emission reductions and from 52 to 73% of aggregated social benefits (including congestion, air quality, CO 2 emissions, noise) expected from ridesharing. This is primarily the result of the modal shift effect, supplemented as ridesharing develops by the distance effect. Although the simplified representation of ridesharing in the baseline model calls for caution regarding these estimates, a sensitivity analysis corroborates the main findings and the prevalence of substantial rebound effects. The paper also investigates to what extent three complementary policies - improving public transit, reducing road capacity or increasing the cost of car travel – might limit the overall rebound effect and thereby maximize the benefits of urban ridesharing. [ABSTRACT FROM AUTHOR]

This paper investigates the environmental impact of urban road freight in the Paris region, focusing on pollutant emissions. We develop a modeling chain including a freight demand model, a multiclass traffic assignment model, and a road emission model. This allows for a detailed representation - spatially and with regard to operations - of urban road freight. We find that while urban road freight represents only 6% of trips and 8% of distances traveled by road in the Paris region, it accounts for 36% of total damages caused by pollutant emissions from road traffic. This is the combined result of light and heavy goods vehicles emitting more than private cars, and of freight traffic being more spatially concentrated (within the city center) than passenger traffic, thereby affecting more population. All in all, the environmental cost of urban road freight is around 2.1 billion € per year. Some policy implications are discussed. [ABSTRACT FROM AUTHOR]

Engineers and planners need information about factors that affect demand for bicycling and walking to plan and manage transportation infrastructure. This paper presents a set of econometric models that summarize the effects of variation in temperature, precipitation, wind speed, dew point, and hours of daylight on daily bicycle and pedestrian trail traffic volumes. We make three contributions to the literature on non-motorized traffic monitoring. First, we summarize trail traffic monitoring results for 32 monitoring stations on multiuse trails in 13 cities in the United States, including locations across seven climate regions and zones classified by the U.S. Department of Energy. The monitoring results include estimates of average daily bicyclists (ADB) and average daily pedestrians (ADP) for the period, January 1, 2014 through February 16, 2016. Second, we introduce the concept of demand returns by testing the parabola form of the weather factors in the models, and measuring the vertex points of demand functions where use shifts from increasing to decreasing or vice versa in response to linear changes in the weather variable. Third, we compare regional elasticities for each weather variable for both bicyclists and pedestrians. Our results show (1) mean daily trail traffic varies substantially in response to variations in weather, with greater elasticities for temperature than precipitation and other weather variables; (2) the parabola form works well for variables such as temperature, where trail use is associated with warmer temperatures, but only up to a point at which higher temperatures then decrease use; and (3) bicyclists and pedestrians respond differently to variations in weather, and their responses vary both within and across regions. Transportation planners and trail managers can use these results to estimate the effects of weather and climate on trail traffic and to plan and manage facilities more effectively. [ABSTRACT FROM AUTHOR]

Rising population, income and urbanization are increasing urban passenger transport demand in India. Energy and emissions intensities associated with conventional transport are no longer sustainable vis-a-vis energy security, air quality and climate change. Cities are seeking transport roadmaps that jointly mitigate these risks. Roadmaps vary across cities, but approach to delineate actions is common: (i) ‘representative vision’ that articulates long-term goals, (ii) methods for comparative scenarios assessment, and (iii) quantification of co-benefits to prioritize actions. This paper illustrates application of quantitative modeling to assess development and environmental co-benefits for Ahmedabad city. The paper constructs two transport scenarios spanning till 2035. The bifurcating themes are: (i) Business-as-Usual (BAU) and Low Carbon Scenario (LCS). The quantitative assessment using Extended Snapshot (ExSS) Model shows that transport activity shall result in four-fold increase in energy demand under BAU from 2010 to 2035. Three key contributors to CO 2 mitigation under LCS in merit order are: (i) fuel switch, including decarbonized electricity, (ii) modal shift, and (iii) substitution of travel demand. Scenarios analysis shows that LCS improves energy security by reducing oil demand and also delivers air quality co-benefits – reducing 74% NOx and 83% PM 2.5 from the passenger transport sector compared to BAU in 2035. Finally, the paper argues that cities in developing countries can leverage carbon finance to develop sustainable and low carbon mobility plans that prevent adverse infrastructure and behavioral lock-ins and prompt low carbon development. [ABSTRACT FROM AUTHOR]

• Land transportation pathways towards 1.5 °C scenario for 4 countries are presented. • The avoid/shift/improve approach is used to create a 1.5 °C scenario for each country. • Ambitious pledges in transportation will be necessary for updated countries' NDCs. • A 1.5 °C scenario will require the implementation of a wide range of policies and measures. • These will reflect commitments tovery low CO 2 vehicle technologies, energy systems, and travel patterns. Decarbonizing transportation in emerging economies will be one of the key challenges in global climate change mitigation efforts. In this paper, pathways are developed towards achieving a 1.5° degree scenario for land-transport for four emerging economies (Brazil, India, Kenya and Vietnam). The aim is to highlight the key opportunities and challenges for low-carbon transport in countries with rapidly growing mobility demand. The main focus of this paper is to reconcile actual and required emission reduction targets and develop plausible pathways to achieve these targets. The paper also identifies potential strategies and measures for these countries to follow these pathways. The analysis considers the contributions of "avoid" (cutting travel growth), "shift" (to lower CO 2 modes) and "improve" (vehicle and fuel CO 2 characteristics) interventions to decarbonisation scenarios. These scenarios aim to inform renewed Nationally Determined Contributions and shed light on the feasibility of deep decarbonisation pathways that would be in line with the Paris Agreement. Results from this study show that achieving 1.5DS would require dramatic changes in travel patterns, technology and fuels, and major intensification of current policy approaches. Decarbonization solutions will need to include greater use and investment of efficient modes, major shifts toward near-zero carbon fuels such as clean electricity, systems integration, modal shift and urban planning solutions. Although the socio-economic situations and national transport systems differ between the selected countries, some fairly similar strategies appear likely to be core to the mitigation effort, such as rapid growth in light- and heavy-duty vehicle electrification and investments in public transit systems. [ABSTRACT FROM AUTHOR]