Evolution of the TRANSYT model in a developing country

TRANSYT has been used in Chile since the early 1980s for cost–benefit analysis of infrastructure and traffic management projects. It is also the main tool of the Area Traffic Control Unit of Santiago de Chile since mid 1990s. As a result of this experience, many methodological improvements to the model have been done in order to take into account local conditions. This paper presents a review of these methodological as well as practical advances on the TRANSYT model made in the Chilean context during the past 15 years. Issues considered are cruise time distributions, the cycle-time selection method, saturation flows and car equivalents, public transport modeling, peak-hour delay calculation, modeling unsignalized intersections and zebra crossings, and fuel-consumption estimation.