Christopher Zegras

The Built Environment and Motor Vehicle Ownership and Use: Evidence from Santiago de Chile

This paper examines the relationships between the built environment—both ‘neighborhood’ design characteristics and relative location—and motor vehicle ownership and use in a rapidly motorising, developing city context, that of Santiago de Chile. A vehicle choice model suggests that income dominates the household vehicle ownership decision, but also detects a relationship between several built environment characteristics and a household’s likelihood of car ownership. A second model, directly linked to the ownership model to correct for selection bias and endogeneity, suggests a strong relationship with locational characteristics like distance to the central business district and Metro stations. Elasticities of vehicle kilometres travelled (VKT), calculated via the combined models, suggest that income plays the overall largest single role in determining VKT. In combination, however, a range of different design and relative location characteristics also display a relatively strong association with VKT.

The Emergence of Inter-Municipal Collaboration: Evidence from Metropolitan Planning in Portugal

Inter-organizational collaboration as a means for policy coordination has come to be seen as a solution to difficult and complex urban challenges. In Portugal, where metropolitan governance structures are highly fragmented, critics highlight the need for better coordination between municipalities—a situation typical in many countries. We seek to understand the forces behind the emergence of inter-municipal collaboration around land use and mobility issues, using a case study method. Based on nine cases from Portugals two largest metropolitan areas, we test a model of inter-municipal collaboration, attempting to identify the factors and conditions which contribute to the emergence of collaborative relationships. The analysis suggests several points of validation as well as propositions for extending and refining the model. We find that collaboration is facilitated by a combination of positive incentives, ambiguity and flexibility in the institutional system, an external catalyst, existing inter-organizational networks, and specific organizational characteristics. The existence of any one of these factors is not enough. A combination of several factors, possible but apparently uncommon in Portugal, is necessary. This research suggests that the Portuguese planning system may be most likely to achieve metropolitan policy coordination through a metropolitan association that can incentivize collaborative projects.

The costs of transportation in Santiago de Chile: analysis and policy implications

In an attempt to better understand the current transportation situation in Santiago de Chile, this paper provides a framework within which personal expenditures, environmental consequences and social effects can be measured by a common metric, costs. The analysis includes all modes of transport, but has a specific focus on passenger transport modes. The paper presents the cost categories considered and methodologies and assumptions used in deriving the costs, a summary of the total magnitude of costs, a differentiation of internal and external costs, and a cost comparison according to various travel modes. The paper concludes with a brief analysis of the implications of the results for evaluating transport policy and pricing options.

The MCMA Transportation System: Mobility and Air Pollution

As discussed in previous chapters, the rapid growth of the MCMA’s population, motor vehicle fleet, and industrial activity over the latter half of the 20th Century combined with the city’s meteorological and topographical situation has produced extraordinary levels of air pollution. The MCMA is today one of the world’s five largest cities. Until recently, it also held the dubious distinction of being one of the world’s most polluted cities, suffering from serious ozone and particulate pollution for much of the year.

Financing Transport Infrastructure in Developing Country Cities: Evaluation of and Lessons from Nascent Use of Impact Fees in Santiago de Chile

The potential for and limitations to the use of impact fees to finance urban transport infrastructure in developing country cities are assessed, drawing from the specific case of Santiago de Chile. The current state of urban transport infrastructure financing and its inherent complications are first presented. Principles of appropriate impact fee use are then derived from the U.S. experience. These principles are then applied to the recent use of transportation impact fees in Santiago, leading to preliminary recommendations for improvement, including the following: establishing proper overarching legal guidance for their use; taking a uniform approach to their application; clarifying the relationship of impact fees to other user fees and other forms of development exactions; answering the question of who bears the ultimate burden of impact fee costs; and improving the understanding of the effects of transportation impact fees on other public policy goals. From this assessment of the Santiago experience, lessons for other developing country cities are presented.

Cost Estimates of Transport Air Pollution in Santiago, Chile

Findings from a study that attempts to monetize the costs of transport air pollution in Santiago, Chile, are presented. The costs per pollutant used in the study come from a 1994 World Bank study estimating morbidity and mortality costs of air pollution in Santiago, based on productivity losses and treatment costs. Using MOBILE-derived vehicle emissions factors and estimated vehicle distances traveled by various vehicle types, the total estimated transport pollution costs incurred in 1994 are presented. Also presented are estimated average air pollution costs per passenger kilometer traveled for pre- and post-EPA87 standard autos and taxis and pre–and post–EPA91 standard buses, as well as for Santiago’s Metro (urban heavy rail). Future air pollution trends in Santiago are discussed, and a theoretical discussion of the potential application of these cost estimates for transportation policy making in the city is provided.

Smartphone-Based Survey for Real-Time and Retrospective Happiness Related to Travel and Activities

Understanding and incorporating measures of travel and activity well-being in transportation research are critical for the design and evaluation of policies. In recent years, several efforts have been made to quantify travelers’ subjective well-being by using a self-reported state of happiness during participation in various activities or travel patterns. The inadequacies of these conventional survey methods in collecting uninterrupted and comprehensive information have restricted the number of such studies. In this study, a smartphone-based sensing platform was adapted to collect mobility information and measure happiness. Two surveys were conducted with respondents from five continents. Real-time and retrospective happiness measures are compared and explained. Results indicate that different cognitive biases affect the levels of happiness reported by the individuals. In comparison with staying at home, performing work and education activities tends to result in lower levels of happiness, while performing other activities tends to result in higher levels of happiness. Activity duration has a significant effect on real-time happiness but is less significant for retrospective happiness.

Children at Risk: A Comparison of Child Pedestrian Traffic Collisions in Santiago, Chile, and Seoul, South Korea

ABSTRACT Objective: We examine and compare pedestrian–vehicle collisions and injury outcomes involving school-age children between 5 and 18 years of age in the capital cities of Santiago, Chile, and Seoul, South Korea. Methods: We conduct descriptive analysis of the child pedestrian–vehicle collision (P-VC) data (904 collisions for Santiago and 3,505 for Seoul) reported by the police between 2010 and 2011. We also statistically analyze factors associated with child P-VCs, by both incident severity and age group, using 3 regression models: negative binomial, probit, and spatial lag models. Results: Descriptive statistics suggest that child pedestrians in Seoul have a higher risk of being involved in traffic crashes than their counterparts in Santiago. However, in Seoul a greater proportion of children are unharmed as a result of these incidents, whereas more child pedestrians are killed in Santiago. Younger children in Seoul suffer more injuries from P-VCs than in Santiago. The majority of P-VCs in both cities tend to occur in the afternoon and evening, at intersections in Santiago and at midblock locations in Seoul. Our model results suggest that the resident population of children is positively associated with P-VCs in both cities, and school concentrations apparently increase P-VC risk among older children in Santiago. Bus stops are associated with higher P-VCs in Seoul, and subway stations relate to higher P-VCs among older children in Santiago. Zone-level land use mix was negatively related to child P-VCs in Seoul but not in Santiago. Arterial roads are associated with fewer P-VCs, especially for younger children in both cities. A share of collector roads is associated with increased P-VCs in Seoul but fewer P-VCs in Santiago. Hilliness is related to fewer P-VCs in both cities. Differences in these model results for Santiago and Seoul warrant additional analysis, as do the differences in results across model type (negative binomial versus spatial lag models). Conclusions: To reduce child P-VCs, this study suggests the need to assess subway station and bus stop area conditions in Santiago and Seoul, respectively; areas with high density of schools in Santiago; areas with greater concentrations of children in both cities; and collector roads in Seoul.

Enriching Activity-Based Models using Smartphone-Based Travel Surveys

Smartphone-based travel surveys have attracted much attention recently, for their potential to improve data quality and response rate. One of the first such survey systems, Future Mobility Sensing (FMS), leverages sensors on smartphones, and machine learning techniques to collect detailed personal travel data. The main purpose of this research is to compare data collected by FMS and traditional methods, and study the implications of using FMS data for travel behavior modeling. Since its initial field test in Singapore, FMS has been used in several large-scale household travel surveys, including one in Tel Aviv, Israel. We present comparative analyses that make use of the rich datasets from Singapore and Tel Aviv, focusing on three main aspects: (1) richness in activity behaviors observed, (2) completeness of travel and activity data, and (3) data accuracy. Results show that FMS has clear advantages over traditional travel surveys: it has higher resolution and better accuracy of times, locations, and paths; FMS represents out-of-work and leisure activities well; and reveals large variability in day-to-day activity pattern, which is inadequately captured in a one-day snapshot in typical traditional surveys. FMS also captures travel and activities that tend to be under-reported in traditional surveys such as multiple stops in a tour and work-based sub-tours. These richer and more complete and accurate data can improve future activity-based modeling.