Saeid Saidi

• PhD
• Professor (Assistant) at University of Calgary

Extensive work exists on regular rail network planning. However, few studies exist on the planning and design of ring-radial rail transit systems. With more ring transit lines being planned and built in Asia, Europe and the America's, a detailed study on ring transit lines is timely. An analytical model to find the optimal number of radial lines in...

The paper introduces a new framework for analysis of complex urban rail transit networks based on generalized passenger costs. We have developed a robust framework for the long-term planning and modeling of rail transit networks that are idealized in a radio-centric form. The model is used to compare the performance of different rail transit networ...

This paper provides a comprehensive review of literature on integrated infrastructure systems with an emphasis on interdependency types and definitions, complex network abstractions, and on different modeling and simulation techniques. An infrastructure interdependency matrix is presented to provide a better mapping of implementation, utilization,...

The cost associated with the waiting time that passengers incur in a public transit network is one of the main components of total transit travel cost. The cost of a unit of waiting time per passenger is higher than the cost of a unit of riding time or access time. While the assumption of half the headway as the mean waiting time has been widely us...

Waiting cost is usually considered as the highest cost imposed to passengers in transit systems. Efficient planning and operations of transit systems require accurate estimation of passengers' waiting time. While the assumption of half the headway, as the mean waiting time experienced by transit users, has been extensively used in waiting time cost...

Public bus transit service (PBTS) is recognized as a highly effective mode of transportation, offering accessibility, affordability, and adaptability that contribute to its critical role in transportation networks. The extensive literature on PBTS encompasses various aspects, with mathematical programming emerging as a widely employed methodology t...

The Public Bus Transit Network Design Problem and Operations Planning (PBTNDP&OP) remains a core research area within transportation, in particular, because of the emergence of new transit technologies and services. Analytical approaches and mathematical programming are the most commonly applied methodologies to study this problem. Many studies uti...

Among all public transit modes, bus transit systems stand out as the most prevalent and popular. This prominence has spurred a significant body of research addressing various aspects of bus systems. In the literature, analytical approaches and mathematical programming are predominantly used to explore the Public Bus Transit Network Design Problem a...

In this paper, a probabilistic topic modeling algorithm called Latent Dirichlet Allocation (LDA) is implemented to infer trip purposes from activity attributes revealed from smart card transit data in an unsupervised manner. While most literature focused on finding patterns for home and work activities, we further investigated non-home and non-work...

In this paper, we investigated the impact on dwell time of station design, train load, and passenger flow, considering boarding fraction. We employed system-wide automated data sources including automatic passenger counting and automatic vehicle location data in the rail transit system in Calgary, Canada. Regression analyses were conducted to achie...

Transportation networks, which are vital to society’s function, are vulnerable to extreme events like floods. Under the influence of climate change, the intensity and the frequency of these food events are increasing globally at an alarming rate. These events result in a series of flood impacts and associated cascading effects, which reduce the ove...

Intelligent systems have been extensively used to improve the reliability of transport services as a result of technological advances. Despite the technical and methodological achievements, public transportation companies are still facing excessive challenges in assessing the performance and reliability of the system. This study establishes a data-...

Objectives: This study investigated preventive behaviors toward coronavirus disease 2019 (COVID-19) and related factors in a Kurdish Iranian sample. Methods: This online survey was conducted among the population aged 18 and above in Kermanshah Province, in western Iran, in April 2020. Samples were invited and recruited through social media. Data...

In this paper, we investigate the impact of mobility on the spread of COVID-19 in Tehran, Iran. We have performed a time series analysis between the indicators of public transit use and inter-city trips on the number of infected people. Our results showed a significant relationship between the number of infected people and mobility variables with b...

The public transport sector worldwide experienced the worst impact in recent history, in terms of ridership loss, due to the COVID-19 pandemic. The pandemic negatively affected passengers' perceptions of public transport and is likely to make a lasting impact on ridership, trip patterns, and modal share. Without any supportive changes to transit op...

A region's transportation sector is vital to its economic and social health. Transportation systems are also influenced by climate change directly and indirectly and on a variety of spatial and temporal scales. Under a changing climate, many regions around the globe and especially in urban areas, have experienced increases in flood intensity and fr...

Many subway systems operating near capacity face challenges in meeting reliability and level of service targets. This paper examines the effectiveness of various strategies to relieve congestion and increase capacity using a microscopic, agent-based, urban heavy rail simulation model. The Massachusetts Bay Transportation Authority’s (MBTA) Red Line...

A mathematical model was developed and applied to optimize many to one demand-responsive transit (DRT) systems using a zonal strategy. Such a DRT system provides service between a residential area and a terminal. The model is used to design the transit system, with its terminal sitting within the service area, by minimizing costs that are separatel...

Shanghai, China, has the largest metro system in the world, with a network length of more than 550 km. Both Shanghai and Beijing are among the top five cities in terms of ridership, and some of the most important components of their metro systems are the ring transit lines. Many other cities, in China and elsewhere, also envision a ring transit lin...

With increase in population, demand for traffic is increasing tremendously. As a consequence congestion on urban freeways or highways during the morning and evening peak hours is always increasing. This research examines the traffic condition on Highway 2(i.e Deerfoot Trail), Calgary,Canada by providing ramp metering (funded by Government of Canada...

Regression analyses were performed to study the relationship between rail transit network parameters (e.g., length of line, age of the system, network topology) with city parameters (e.g., population, city area, population density). Transit ridership patterns in Europe, Asia, and North America were investigated. Ring transit lines were found to be...

Regression analyses were performed to study the relationship between rail trims it network parameters (e.g., length or line, age of the system, network topology) with city parameters (e.g., population, city area, population density). Transit ridership patterns in Europe, Asia, and North America were investigated. Ring transit lines were found to be...

In this paper, a probe‐based adaptive ramp metering approach has been developed and compared with a detector‐based and pretimed ramp metering approaches using PARAMICS microsimulation model made by Quadstone Limited. Both examined probe‐based and detector‐based ramp metering approaches adopt the same problem formulation; however, they differ by the...

The Western Province of Sri Lanka is a developing urban conglomerate and the economic engine of the nation. In the long run, it will require an upgrade of the existing radial rail lines and possibly one or two partial ring rail lines. We investigate two such partial ring lines based on some theories developed by Saidi (2013) et al.

This paper focuses on assessing the benefits of vehicle-to-vehicle (V2V) communication in high incident cases resulting from extreme conditions, such as adverse weather conditions. V2V capabilities are simulated and tested through the use of two Paramics Applications Programming Interfaces (APIs). One API randomly creates incidents, and the API sim...