Browsing by Author "Grange, Louis de"

Now showing 1 - 13 of 13
  • Thumbnail Image
    Item
    A Logit Model With Endogenous Explanatory Variables and Network Externalities
    (2015) Grange, Louis de; González, Felipe; Vargas, Ignacio; Troncoso, Rodrigo
    A novel logit model is presented that explicitly includes endogeneity in explanatory variables whose values depend on individual choice decisions that involve network externalities or social interactions such as those impacting road congestion or public transport comfort and convenience. The proposed specification corrects for this particular type of endogeneity. The model is derived from a linearly constrained maximum entropy optimization problem that incorporates the network externalities or social interactions causing the endogeneity. It is validated through simulations and an application to a case of transport mode choice in a Chilean city using real data.
  • Thumbnail Image
    Item
    A microeconomic interpretation for the system optimal traffic assignment problem with nonadditive path cost
    (2014) Muñoz, Juan Carlos; Troncoso, Rodrigo; Grange, Louis de
  • Thumbnail Image
    Item
    A Road Pricing Model for Congested Highways Based on Link Densities
    (2017) Grange, Louis de; Troncoso, Rodrigo; González, Felipe
    A road pricing model is presented that determines tolls for congested highways. The main contribution of this paper is to include density explicitly in the pricing scheme and not just flow and time. The methodology solves a nonlinear constrained optimization problem whose objective function maximizes toll revenue or highway use (2 scenarios). The results show that the optimal tolls depend on highway design and the level of congestion. The model parameters are estimated from a Chile's highway data. Significant differences were found between the highway's observed tolls and the optimal toll levels for the two scenarios. The proposed approach could be applied to either planned highway concessions with recovery of capital costs or the extension or retendering of existing concessions.
  • Thumbnail Image
    Item
    Aggregate estimation of the price elasticity of demand for public transport in integrated fare systems: The case of Transantiago
    (2013) González, Felipe; Muñoz, Juan Carlos; Troncoso, Rodrigo; Grange, Louis de
    Price elasticities of demand for public transport are a key determinant in evaluating the impact of changes in fares on user flows, yet in many integrated fare transit systems, estimating these indicators is often hampered by two realities: the fare changes for different modes are implemented simultaneously and their magnitudes are highly correlated. This strong collinearity is particularly problematic in linear or log-linear models, commonly used for elasticity estimation, and in a case study of Santiago, Chile, robust results with such specifications proved elusive. This paper presents a method based on discrete choice models to estimate the elasticities in an integrated fare system that overcomes these econometric problems, generating results that are both robust and consistent with those reported in the literature. The proposed models are also easy to update and evaluate.
  • Thumbnail Image
    Item
    An empirical evaluation of the impact of three urban transportation policies on transit use
    (01/07/2012) Grange, Louis de; Troncoso, Rodrigo; González, Felipe
    The impact on transportation mode choice of policies implementing metro network expansion, fare subsidies and automobile use and ownership regulation was evaluated econometrically using data for 41 world cities. Controlling socioeconomic and demographic variables, it was found that an increase in metro network extension of 10% generates an average decrease in automobile use of 2%. The results also showed that regulation of automobile use or ownership leads to a significant rise in public transit use. By contrast, no evidence was discovered suggesting that transit fare subsidies produce significant increases in transit ridership. (C) 2012 Elsevier Ltd. All rights reserved.
  • Thumbnail Image
    Item
    Effects of environmental alerts and pre-emergencies on pollutant concentrations in Santiago,Chile
    (01/12/2012) Troncoso, Rodrigo; Grange, Louis de; Cifuentes, Luis A.
    To reduce air pollution levels in Santiago, Chile on days when the weather is expected to create poor ventilation conditions and increased air pollutant concentrations, the responsible authorities impose temporary restrictions on motor vehicles and certain industrial activities. We estimate the impact of these restrictions on the city's air quality using data collected by a network of monitoring stations. The estimates show that the restrictions do reduce the average concentrations of coarse and fine particulate matter, carbon monoxide and nitrogen oxide (both gases are emitted mainly by vehicles). However, no significant changes were found in the sulfur dioxide concentrations, which are primarily the result of industrial processes. (C) 2012 Elsevier Ltd. All rights reserved.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Estimating the impact of incidents on urban controlled-access highways: an empirical analysis
    (2017) Grange, Louis de; Troncoso, Rodrigo; Odeh, Nicolás; González, Felipe
    An empirical analysis is developed that quantifies the impact of different types of traffic incidents on the speed and maximum flow averages of vehicles on a controlled-access highway. The incident types considered include damage to highway infrastructure, vehicle rollover, crashes (into stationary objects), collisions (with moving vehicles), rain, fog, vehicle breakdowns, pedestrians on roadway, etc. Using real-world data from Chile’s most heavily used urban motorway/freeway, estimates of incident impacts on speed are generated using a multiple linear regression model incorporating instrumental variables to correct for endogeneity. Flow results are then generated using the fundamental traffic equation relating speed, flow and density. A ranking of the impacts on highway traffic of the different incident types based on incident frequency as well as impact size demonstrates that for the real case studied, the incidents with the greatest cumulative effect are (in order of magnitude) vehicle breakdown, collisions and rain.
  • Thumbnail Image
    Item
    Fare evasion in public transport: A time series approach
    (2017) Troncoso, Rodrigo; Grange, Louis de
    An econometric model is presented that identifies the main variables explaining evasion of fare payment on a public transport system. The model uses a cointegration approach. The model parameters are estimated using data from the Santiago (Chile) bus system, where evasion has been measured at approximately 28%. The main results of the model are that (i) a 10% increase in the fare raises evasion by 2 percentage points and (ii) a 10% increase in inspections lowers evasion by 0.8 percentage points. An increase in unemployment, the third explanatory variable in the model, tends to induce a decrease in evasion, and vice versa. This counterintuitive finding may be explained by the fact that those most vulnerable to job loss, and more likely to evade than the average user due to economic necessity, tend to reduce their use of the bus system when unemployment rises and increase it when unemployment falls. Our results suggest a revision of the evasion control policy in Santiago to improve its effectiveness, and to link inspection efforts to fare increases or to decreases in unemployment.
  • Thumbnail Image
    Item
    Impact of the dedicated infrastructure on bus service quality: an empirical analysis
    (2019) González, Felipe; Valdivieso, Vicente; Grange, Louis de; Troncoso, Rodrigo
    An econometric analysis is conducted to quantify the impact of different variables on the service quality of the Santiago, Chile bus system. The indicators tested as measures of service quality are the average bus speed, the bus trip time coefficient of variation and the bus headway coefficient of variation. The analysis uses peak hour data obtained for all the routes served by the system’s various concessionaire operators. A separate multiple linear regression model is estimated for each indicator, with the latter as the explained variable. The main explanatory variables are a series of design factors representing different types of dedicated route infrastructure and the incorporation in some routes of segments of urban motorway. The results of the models show that the existence of dedicated bus route infrastructure positively impacts all three service quality indicators. The use of motorway segments in particular has a major positive effect on average speed. The model estimates also reveal that the main explanatory factor in headway variability at the end of a route is the headway variability at the start of it, the latter factor determined by operator management decisions regarding bus despatches.
  • Thumbnail Image
    Item
    Impacts of vehicle restrictions on urban transport flows: The case of Santiago, Chile
    (01/11/2011) Grange, Louis de; Troncoso, Rodrigo
    Regression models are employed to quantify the effects of vehicle restrictions on private and public transport passenger flows in Santiago, Chile using trip flow data for cars, buses and the city's Metro rail system. Estimates are derived for the effects of two restrictions: a permanent measure applied from April through August 2008 to vehicles without catalytic converters and additional measures that banned the use of vehicles with catalytic converters between 7:30 am and 9 pm on days declared as environmental "pre-emergencies" due to high air pollution levels. The estimates show that the permanent restriction had no impact on the use of private cars while the additional restriction curtailed their use by 5.5%. Also, on pre-emergency days the flow of passengers to the Metro increased by about 3% while the bus network showed no statistically significant increase. The pre-emergency restrictions thus had an effect on the ridership of the Metro but not on the bus network as alternatives to the use of private cars. (C) 2011 Elsevier Ltd. All rights reserved.
  • Thumbnail Image
    Item
    Shortcomings in urban road pricing
    (2015) Grange, Louis de; Troncoso, Rodrigo
  • Thumbnail Image
    Item
    The impact of commute time on the Gender wage gap: an empirical analysis
    (2021) Troncoso Olchevskaia, Rodrigo; Grange, Louis de; Rodríguez, Danae
    The gender wage gap for the city of Santiago, Chile and its explained and unexplained portions are analysed using the Oaxaca-Blinder decomposition with data from CASEN 2017, the Chilean household survey. A novel feature of the analysis is the inclusion among the explanatory variables of commute time. Wage equations for men and women are estimated using three different methods: ordinary least squares, twostage least squares and the Heckman selection model. The estimates of the gap vary depending on the method between 0% and 9%. The decomposition of the gap reveals that between 6% and 17% of the gap is unexplained (i.e., due to discrimination). Commute time is found to account for 10% to 47% of the logarithmic wage gap explained by worker characteristics.

Implementado por OpenGeek Services