Comparison on Turn Costs in Accessibility Models. Case Study: Manizales, Colombia

Santiago Cardona,Carlos Moncada,Diego Escobar

doi:10.5539/mas.v12n8p59

Abstract

The transport models have taken great relevance in the last decades because they help to make big urban planning decisions. In this sense, supply models, such as global average accessibility, seek to approach more and more to reality in order to represent it in the best possible way. In this research article, we compare the different penalties for turns used in the global average accessibility models in the city of Manizales, being compared with the preliminary results of a research thesis in which the penalties for turns were calculated by means of an empirical methodology that analyzes different road intersections in the city. At the end, the savings gradient method is used to measure the differences between the different calculated scenarios.

Highlights

Over the years, transport planners have created tools that allow a more efficient projection of this important section in the conception of the city; transportation models have become an indispensable tool given the investment in time and budget related to the different policies associated with them, such as the construction of new road infrastructure projects and the implementation of new public transport systems such as metro lines, aerial tramways or BRT (An, Teng, & Meng, 2008; Escobar & Garcia, 2011)
This scenario represents the global average accessibility model calculated in previous research in the city of Manizales (Escobar & Garcia, 2012, Escobar et al, 2016, Moncada et al, 2018, Zuluaga & Escobar, 2017), where 1 min was used for the right turn and 1.15 min for the left turn as turn costs in the model, determined in a subjective manner
This scenario corresponds to the global average accessibility, which includes the turn costs calculated using the empirical methodology developed in a Master's research at the National University of Colombia, Manizales, which is in publishing process

Summary

Introduction

Transport planners have created tools that allow a more efficient projection of this important section in the conception of the city; transportation models have become an indispensable tool given the investment in time and budget related to the different policies associated with them, such as the construction of new road infrastructure projects and the implementation of new public transport systems such as metro lines, aerial tramways or BRT (An, Teng, & Meng, 2008; Escobar & Garcia, 2011). Demand models seek to represent and predict what the inhabitants of a city require in terms of transport, while the models of supply, as the name implies, measure the transport supply found in a city or region (Ortúzar & Willumsen, 1994). According to Ortúzar and Willumsen (1994), the work of transportation modelers is to represent reality in the most accurate possible way, taking into account different factors such as average speeds of the road network, delays due to traffic jams and even turn costs of the different vehicles, for this reason, in this research article, the calculated turn costs gotten in an empirical way in the city of Manizales are used to measure the global average accessibility, as a transportation supply model. A comparison is made with respect to the turn costs used in previous investigations, which had been determined subjectively for the 2011 Mobility Plan (Escobar & Garcia, 2012)

Methods

Results

Conclusion