Luis A. Guzman

Optimal and Long-Term Dynamic Transport Policy Design: Seeking Maximum Social Welfare through a Pricing Scheme

ABSTRACT This article presents an alternative approach to the decision-making process in transport strategy design. The study explores the possibility of integrating forecasting, assessment and optimization procedures in support of a decision-making process designed to reach the best achievable scenario through mobility policies. Long-term evaluation, as required by a dynamic system such as a city, is provided by a strategic Land-Use and Transport Interaction (LUTI) model. The social welfare achieved by implementing mobility LUTI model policies is measured through a cost-benefit analysis and maximized through an optimization process throughout the evaluation period. The method is tested by optimizing a pricing policy scheme in Madrid on a cordon toll in a context requiring system efficiency, social equity and environmental quality. The optimized scheme yields an appreciable increase in social surplus through a relatively low rate compared to other similar pricing toll schemes. The results highlight the different considerations regarding mobility impacts on the case study area, as well as the major contributors to social welfare surplus. This leads the authors to reconsider the cost-analysis approach, as defined in the study, as the best option for formulating sustainability measures.

Optimization of transport measures to reduce GHG and pollutant emissions through a LUTI modeling approach

ABSTRACT This article compares the potential of four transportation policies designed to reduce greenhouse gases and pollutant emissions in urban areas. The policies analyzed include both pricing policies aimed to increase car costs and fleet renovation. The study applies a land-use and transportation interaction model combined with an optimization algorithm that provides the optimal design of each policy. The results show how each policy, or combination of policies, affects long-term modal share, trip length, trip times, and vehicle kilometers traveled. Those are the explanatory variables for modeling the emissions at a city level. The policies are tested in the metropolitan area of Madrid (Spain). The evaluation framework allows testing the effectiveness of these policies for various future policy measures at two different geographical scales. The impact of a fuel tax and a major vehicle fleet renewal are simulated for the whole Madrid region. Policy packages including a congestion (road) charge and increased parking fees are tested only in the central business district of the city. The results of the study show that of all the policy packages tested involving higher fuel prices are expected to have the greatest effect on achieving the environmental targets. They also show that technological improvements in the vehicle fleet are insufficient to reduce CO2 emissions levels per se, although they do contribute to a decrease in pollutant emissions owing to improved engine performance and reduced gas consumption and emissions when used together with other policy instruments. Finally, local measures such as road pricing and parking fees fulfill local objectives in the central area of the city but cause negative externalities on the surrounding areas.

Integration of Congestion Pricing and Intertemporal Preference Rate in Social Welfare Function

Many researchers have used theoretical or empirical measures to assess social benefits in transport policy implementation. However, few have measured social benefits by using discount rates, including the inter-temporal preference rate of users, the private investment discount rate, and the intertemporal preference rate of the government. In general, the social discount rate used is the same for all social actors. This paper aims to assess a new method by integrating different types of discount rates belonging to different social actors to measure the real benefits of each actor in the short term, medium term, and long term. A dynamic simulation is provided by a strategic land use and transport interaction model. The method was tested by optimizing a cordon toll scheme in Madrid, Spain. Socioeconomic efficiency and environmental criteria were considered. On the basis of the modified social welfare function, the effects on the measure of social benefits were estimated and compared with the classical welfare function measures. The results show that the use of more suitable discount rates for each social actor had an effect on the selection and definition of optimal strategy of congestion pricing. The usefulness of the measure of congestion toll declines more quickly over time. This result could be the key to understanding the relationship between transport system policies and the distribution of social actors’ benefits in a metropolitan context.

Linking a transport dynamic model with an emissions model to aid air pollution evaluations of transport policies in Latin America

ABSTRACT Considering the key role of the transport sector in the economy and its contribution to greenhouse gas (GHG) and local air pollutant emissions, the development of integrated techniques to evaluate long-term urban trends should be a top priority for creating a more sustainable society. This paper presents an integrated model for reliable estimation of passenger transport emissions of local pollutants and CO2 using an integrated Land-Use and Transport Interaction (LUTI) model in Bogota (Colombia) between 2010 and 2026. Two additional scenarios are modelled to illustrate the use of the model to evaluate the impacts of possible policy interventions. An alternative system dynamics approach is proposed as part of a structured decision-making process. The methodology uses causal loop diagrams (CLD) from systems dynamics to explain cause-and-effect relations, through linking the transport emissions and transport subsystems. The emissions model considers 11 different vehicle categories in total and emission factors for CO2, NOx, THC and PM2.5 were established using local data collected with portable devices and from other available secondary sources. Adjustment factors were established in order to account for ageing of vehicles, technology improvements and changes in category distributions. The development of a general framework based on dynamic systems for assessing long-term emissions estimations according with the particular transport systems is needed for effective sustainable transport planning. The inclusion of adjustment factors for ageing and technology changes provides more reliable projections and helps identify important long-term trends in the emissions inventory. The scenarios proposed are meant to show the results obtained by the model to assist the decision-making process and do not represent current measures in the city or the best practices available. Due to an increase in the use of the private car transport, CO2 emissions will continue to grow in Bogota despite possible technology improvements. Results show that the use of natural gas in the public transport fleet would imply considerable emission reductions in all studied species, being this an alternative technology while electric buses become financially viable.

Fuel Tax Levels Necessary to Achieve the Agreed Reduction Targets of CO2 Emissions. The Case of Madrid

Sustainable urban areas are widely considered a promising target for every city. Different policies are being designed in order to tackle the multifaceted range of transport-related problems in urban agglomerations and therefore contribute significantly to the overall quality of life in cities. The recently published communication “Green Paper - Towards a new culture for urban mobility” [1], clearly says that “European towns and cities are all different, but they face similar challenges and are trying to find common solutions”: for making our cities sustainable. This is not a minor task. Over 60% of the population lives in urban areas and 85% of the EU’s gross domestic product is created in urban areas [1,2].

Accessibility, Affordability, and Addressing Informal Services in Bus Reform: Lessons from Bogotá, Colombia

Many cities in the developing world are reforming transit by formalizing bus services to capture user and nonuser benefits. A forerunner in transit reform, the city of Bogotá, Colombia, first implemented the TransMilenio bus rapid transit (BRT) system and then more recently undertook a large-scale initiative to formalize and regulate traditional urban buses in the city. This integrated public transport system [Sistema Integrado de Transporte Público (SITP)] is transforming Bogotá’s traditional urban bus system into a regulated, concessionary system with restructured bus routes that integrates operations, fares, and infrastructure with the TransMilenio BRT. An investigation was conducted to determine whether the SITP has increased affordability and employment accessibility for public transit users in Bogotá. Results revealed that most accessibility improvements resulted from the recent expansion (and significantly higher speeds) of TransMilenio rather than the SITP. Results of an analysis conducted with budget constraints to determine affordable accessibility indicated that employment accessibility was reduced overall; however, the new integrated fare increased accessibility over traditional buses, especially on the periphery and in southern areas of the city, as a result of reduced transfer costs. Overall, results partly explain the lack of enthusiasm for the bus reform process on the part of public transit users and the political discomfort that becomes apparent when embarking on this process in developing-world cities. Also, more incremental, flexible reform might be crafted for public transportation systems that are dominated by informal services.

A strategic and dynamic land-use transport interaction model for Bogotá and its region

ABSTRACT This paper presents an integrated and strategic model to simulate the dynamic interaction processes between land-use and transport at an aggregate level in Bogotá region. The model uses Causal Loop Diagrams from Systems Dynamics to explain cause and effect relations and incorporates a calibration for the base-year. This model is inspired by the basic hypothesis of the MARS model, although due to the particular characteristics of the study area, it was necessary to make changes. In cities like Bogotá, there is a lack of understanding of the importance of land-use and transport integration challenges, a focus mainly on the short term, a limited knowledge about quantification of the impact of integrated policies, and uneven information availability. Data limitation has been identified as a significant limitation. Consequently, innovative approaches are required in developing cities to adapt to situations where limited information is available. This paper describes the basis, capabilities, and potential uses of LUTI-Bogotá model.

Fare discrimination and daily demand distribution in the BRT system in Bogotá

Bogotá transport authority changed Bus Rapid Transit (Transmilenio) fares in August 2012 to manage congestion, particularly during peak hours. They reduced fares and implemented fare discrimination between peak and off-peak hours to balance demand and make the system more affordable. To estimate the variation in the relative distribution of daily demand between peak and off-peak hours, we used information pertaining to passenger demand on working days. Our main data source was the number of entrances into Transmilenio stations daily between 2011 and 2013. The data before the fare intervention was gathered between March 2011 and July 2012. Post intervention data was gathered between August 2012 and December 2013. We assumed that the users’ observable characteristics did not change either before or after the intervention was carried out. The fares decreased from a flat fare of COP 1750 (1 USD = 1780 COP in August 2012) to COP 1700 in peak hours and to COP 1400 in off-peak hours. This paper proposes a fixed effects model to estimate the effect of fare reduction in the ratio between peak and off-peak ridership hours. The results suggest that fare reduction produced changes in demand behaviour between peak and off-peak hours, reducing the peak to off-peak demand ratio (P/oP) by around 9%. This change has different levels of impact depending on the income levels associated with each Transmilenio station, with a stronger impact in low-income zones.

PW 1092 Prevalence of behavioral risk factors for road traffic injuries in three south american cities

Road traffic injuries (RTIs) are an important cause of death and injury in Colombia and Brazil. This burden is not uniform across countries and cities. Understanding these differences and similarities in road traffic behaviors is key in designing effective RTI interventions. This study is aimed to assess such differences by comparing observed road safety behaviors in three South American cities, Bogotá (Colombia), and São Paulo and Fortaleza (Brazil). As part of the Bloomberg Initiative for Global Road Safety (BIGRS), observational studies were conducted in Bogotá, Fortaleza, and São Paulo. Trained observers recorded road safety behavior (speeding, helmet use, seatbelt use and drink driving) every six months between August 2015 and September 2017. Around 1.5 million observations in these risk factors have been collected throughout six rounds of data collection. It was found that Bogotá and São Paulo had varying rates of speeding, very dependent on changes in policy and enforcement circumstances, whereas Fortaleza maintained relatively high and stables rates. Rates of seatbelt and correct helmet use among all passengers were higher in São Paulo than Bogotá and Fortaleza. Drink driving prevalence was higher in Sao Paulo than Fortaleza and Bogotá. Fortaleza has experienced a reducing trend in drink driving prevalence throughout the project. In São Paulo, refusal rates reached 76%. Important regional differences in road safety risk factors highlight the need for tailored interventions in South American cities. Speeding is a priority for Bogotá and Fortaleza. São Paulo’s alcohol results illustrate the urgency for drink driving-based interventions and correct helmet use is an increasingly important need in Bogotá and Fortaleza. These results are being used to develop specific interventions for BIGRS. These results are of interest for policy makers in Latin American cities and other middle-income countries where these interventions can be piloted and if effective, scaled up and replicated.