In early 2019 I joined the supervisory team of a Master of Transport Engineering student from Tarbiat Modarres University, Hamid Rezaei. Hamid has been a very motivated student and even after his graduation in Sep 2019, we have continued to formulate more advanced models. I am very keen on this research because it is the first behavioural study on Tehran's congestion pricing scheme.

Background:

Tehran’s congestion charging scheme is in place since 1979, to reduce the use of private vehicles and air pollution. This scheme covers a downtown area which mostly consists of traditional bazaars, commercial land uses and works activity centres, with low night-time residential population but very high day-time activities. Tehran had a flat area-licensed scheme until 2019 and in the quest for providing a more equitable and effective scheme, city managers are seeking to modify the congestion pricing scheme. So, it motivated us in this study to investigate the mode choice behaviours under a time-based and variable fee scenario. Accordingly, in this hypothetical scenario the user is charged based on number of hours spending in the pricing zone, and the charging fee is cheaper if the trip starts during non-peak hours.

Our Research Objective:

There has been little discussion directed to the examination of hourly-based versus flat pricing scheme in the literature. The majority of studies have examined the impact of pricing before the implementation phase. Considering that in our study, the participants have a better understanding of the associated costs and benefits of purchasing the permit and using private vehicle, the research efforts in this stage is essential. Plus, undertaking analysis is important for different cities.

Thus, we targeted two research questions as:

1. How much a revised pricing scheme (e.g. hourly-based scheme) can affect the travel behaviours including modal shift, change in travel time or trip cancellation?

2. How do the effects of pricing in cities differ (particularly cities with high levels of congestion and car dominance like Tehran)?

• What are the determinants of modal choice and changes in trip as a result of changes in pricing?

• How much the demand for private cars is elastic with respects to the pricing fee?

A survey was administrated in February 2018 among all different types of travelers (4,164 complete responses)

• Respondent’s travel specifications for a typical trip to the congestion pricing zone

• Choice experiments

• Socio-demographic characteristics of travellers

We formulated advanced discrete choice models (Generalized Mixed Logit model, Latent Class model, Error Component model) in order to capture the correlation between travel choice alternatives, the panel effect and accounting for scale and taste heterogeneity.

This research has been submitted to a journal and is under review. The initial results were presented in the Bridging Transport Researcher (BTR) online conference in January 2020, and you can download the slides here.

Download Presentation Slide