Konstantinos Kepaptsoglou

National Technical University of Athens | NTUA · School of Rural and Surveying Engineering

Walking is both a sustainable transportation option and an easy physical activity. Despite the clear health, environmental and economic benefits, many people are reluctant to walk to their destinations because it can be tiring or time-consuming; therefore, incentives are often needed to encourage walking. This paper presents a novel application (In...

Illegal parking is a widespread issue in urban environments, leading to significant adverse effects on traffic flow, public safety, and the aesthetics of streetscapes. This paper introduces an innovative methodology for the identification and analysis of illegal parking hotspots. To achieve this, a custom Web-GIS platform is developed that employs...

Street classification is crucial in urban and transportation planning. Conventional approaches prioritize car movement, while recent ones emphasize sustainable modes like walking, cycling, and public transport. However, the literature on sustainable street classification remains limited. Hence, this study aims to develop a method for reformulating...

To achieve net zero emissions from ships by 2050 and align with the IMO 2023 GHG strategy, the maritime industry must significantly increase zero-emission vessels by 2030. Transitioning to fully electric ferry lines requires enhanced energy supply through renewable energy sources (RES) for complete GHG mitigation and net-zero emissions. This study...

Safety concerns expressed by micro-mobility users seem to practically constrain the use and flexibility of these new modes. This paper introduces a new, parametric agent-based modeling approach for simulating micro-mobility, using MATSim as a platform. Perceived safety is introduced as a factor, which affects travel behavior of micro-mobility modes...

Shared Autonomous Vehicles (SAVs) are expected to have a transformative role in future transportation systems, by reducing vehicle ownership, helping in alleviating congestion, improving accessibility and traffic safety, and changing travel behavior and urban infrastructure. The potential introduction of SAVs in transportation systems has triggered...

Micro-mobility transport modes like e-bikes and e-scooters promise higher flexibility when covering the first/last mile trip from/to the public transport stop/station to the destination point and vice-versa. However, safety concerns about riding a micro vehicle in mixed traffic limit the flexibility of shared mobility modes and make conventional on...

New transport strategies, which aspire to create sustainable and resilient cities, prioritize active and public transport modes. This paper investigates the differences in accessibility, mobility and activity patterns as a result of radical road space allocation changes. To do so, the TRANUS Land Use and Transport Interaction model is utilized. Als...

Bicycle-oriented multimodality (cycling and fixed-route public transport) could be considered as an efficient tool in developing a sustainable transport system offering adequate transport services to everyone. This study, therefore, explores whether multimodality can support transport equity in a metropolitan urban environment. To this end, a combi...

The reduction of speed limits in urban roads through traffic calming schemes intends to ensure safer traffic conditions among road users by reducing the probability related to the occurrence of severe accident. Looking it from a different perspective, traffic calming measures can potentially resolve congestion problems at the same time by lowering...

A disruption of metro services can have a negative impact in the performance of a city’s transportation system and hinder mobility needs of travellers. Investigating the vulnerability of metro systems is required for planning mitigation actions, such as bus substitution services. This study develops a model, which consists of a bipartite graph and...

Electric scooters (e-scooters) have become popular in numerous urban areas worldwide, largely due to their positive impact on the environment and the convenience they offer for commuting. However, despite their significant role in the transportation system, there is currently no available simulation software that adequately models their dual behavi...

Modeling of Electric scooters (e-scooters) and prediction of their impacts in the transport system is challenging due to their dual drive behavior i.e., from vehicles' roadway to pedestrians' sidewalk. This study aims to develop a model to integrate e-scooter routing process in an agent-based model, namely: MATSim. The developed model is built on t...

The transportation sector contributes significantly to global warming, as well as to urban fabric problems such as traffic congestion, traffic accidents, noise pollution, and air pollution. A shift from fossil fuels to renewable sources and from motorized to non-motorized modes is now considered essential to create sustainable communities. Walking...

The sustainability of maritime activities is increasingly gaining interest, with the shipping sector actively focusing on decarbonization efforts. Throughout the years, researchers have considered slow steaming for improving the environmental footprint of maritime networks. In order to assess such strategies’ effectiveness on existing emissions, re...

The objective of this study is to develop and present a mobility dashboard for the AMA to explore traffic flow variations and understand mobility patterns from 2020 until today. To do so, relative indicators like the additional travel time-travel delay, average travel speed and the ratio of peak travel time to off-peak travel times are estimated co...

Network science offers valuable tools for planning and managing public transportation systems, with measures such as network centralities proposed as complementary predictors of ridership. This paper explores the relationship between different cases of passenger flows at metro stations and network centralities within both metro and alternative publ...

Using Unmanned Aerial Vehicles (UAVs), commonly referred to as “drones”, as a supplementary mode for last-mile deliveries has been a research focus for some years now. Motivation lies in the reduced dependency on Conventional Vehicles (CVs) and fossil fuels and in serving remote areas and underprivileged populations. We are building a flexible, mod...

Shared autonomous vehicles (SAVs) aspire to change not only vehicles but also the way people and goods move in urban areas. However, the promotion of such services, that is, whether travelers are willing to share their trips with other service users, is still a challenge. This study aims to examine the contributory factors that influence the willin...

Shared space is an unconventional concept that is not based on formal rules and standards, as it encourages road users to share the same road space with little physical or visual separation. Consequently, this concept creates intriguing research questions that have not been fully answered yet, i.e., a) can a shared space road section produce more p...

Impact evaluation has become one of the core objectives of the transport sector worldwide towards improving its sustainability performance. This study aims to provide a comprehensive overview of the impacts in the field of escooter services. A systematic literature review is conducted on scientific peered- review journal publications in the English...

Shared space assumes that the elimination of physical segregation and traffic control measures forces road users to become more alert, move at lower speeds, and rely on the environmental context for negotiating movement. Still, pedestrians tend to feel reluctant about sharing the space with motorized traffic triggering a coexistence problem. By inv...

Electric scooters (e-scooters) have become popular in many urban areas around the world due to their contribution in the reduction of environmental impacts and the convenience to purchase and use them. Due to their innovative role within the transport system, a simulation software for modeling their dual behavior is not yet available. This research...

In this study, intraday correlations between station centralities and ridership at stations of the Athens metro system in Greece are explored. An unweighted L-space representation of the physical metro network is developed, and degree, closeness and betweenness are selected as station centrality measures. Hourly smart-card data are used for represe...

E-cargo bikes, i.e., electric bicycles equipped with baskets for transporting goods, are perceived as an advantageous solution for urban last-mile logistics. Particularly for short distances and low volumes of goods, the use of e-cargo bikes is ideal in urban areas where access of conventional cars may be prohibited. In this context, this study pre...

Taxis are popular and convenient transport options in urban areas, yet they are often a target for complaints with respect to service quality and driver behavior. Understanding taxi driver behavior is important, since they are responsible for travelers’ safe, efficient, and convenient commuting. This paper investigates taxi drivers’ behavioral aspe...

The electric scooter (e-scooter) is an increasingly popular transport mode in urban areas at global level. As an alternative form of shared micromobil-ity in cities, e-scooter sharing systems were first introduced in the United States in 2017. Since then, they have spread in Europe, Asia, and Australia. In order to evaluate their sustainability per...

Network science offers valuable tools for planning and managing public transportation systems, with measures such as network centralities proposed as complementary predictors of ridership. This paper explores the relationship between different cases of passenger flows at metro stations and network centralities of both metro and alternative public t...

E-scooters aspire to provide flexibility to their users while covering the first/last mile of a multimodal trip. Yet, their dual travel behavior, i.e., utilizing both vehicles' roadways and pedestri-ans' sidewalks, creates new challenges to transport modelers. This study aims to model e-scooter riding behavior in comparison to traditional urban tra...

Complex network characteristics such as centralities have lately started to be associated with passenger flows at metro stations. Centralities can be leveraged in an effort to develop fast and cost-efficient passenger flow predictive models. However, the accuracy of such models is still under question and the most appropriate predictors are yet to...

1 Active-mode oriented multimodality (cycling and fixed-route public transport) could be considered as an 2 efficient tool in developing a sustainable transport system offering adequate transport services to 3 everyone. This study, therefore, aspires to explore whether multimodality can support transport equity in 4 a metropolitan urban environment...

Emerging forms of shared mobility call for new vehicle routing models that take into account vehicle sharing, ride sharing and autonomous vehicle fleets. This study deals with the design of an optimal route network for autonomous vehicles, considering both vehicle sharing and ride sharing. The problem is modeled as a one-to-many-to-one vehicle rout...

E-scooter sharing services been grown exponentially within the last five years. They are based on the flexibility of accessing dense urban areas without specialized infrastructure. In modern cities, there are diverse road environments that impact the comfort, and therefore the attractiveness, of micro-mobility services. This study aims to investiga...

Modeling of electric scooters (e-scooters) and prediction of their impacts in the transport system is challenging due to their dual drive behavior i.e., from vehicles’ roadway to pedestrians’ sidewalk. This study aims to develop a model to integrate e-scooter routing process in an agent-based model, namely: MATSim. The developed model is built on t...

Worldwide, taxis hold a prominent position in urban mobility, as they offer comfortable and convenient transportation services. Recent technological developments create both new opportunities and limitations in the taxi industry and therefore regulatory reforms are required for the taxi market to properly adjust to and benefit from technological in...

The advent of connected vehicle technology brings forth a new set of possibilities for more efficient traffic control. Indeed, the ability to consider driver-specific attributes, such as value of time or willingness to pay, in intersection management through advanced communication protocols allows for reducing individual delay costs. In this contex...

Battery-assisted trolleybuses (BATs) are among the options to be considered for electrifying bus fleets in cities, with established trolleybus catenary networks. BATs charge on the move using existing trolleybus catenaries and can extend their routes using onboard batteries. As such, in cases where thermal bus lines overlap to some extent with a tr...

Efficient timetable and speed profile determination are critical in improving the energy performance of railway systems. Relevant speed profile optimization models for railway systems typically aim at the minimization of energy consumption and passenger waiting times. Still, passenger comfort during the accelerations and decelerations of the train...

Technological changes in the automobile industry accelerate the development of alternative fuel vehicles and automated driving. These changes affect the vehicle fleet mix in urban areas, and affect the total cost of ownership (TCO) per vehicle technology. The goal of this paper is to expand the traditional TCO model to enable the comparison of vehi...

E-scooter sharing services have grown exponentially in many cities of the world within the last 10 years, mainly with the goal to serve first/last mile trips. Compared to other shared mobility modes (e.g., autonomous buses and electric taxis), for which Agent-based Models (ABMs) have been applied in many cases, just a few studies attempted to simul...

The transition to new forms of urban transport, which are environment friendly, efficient, and cost-effective has become a pressing issue of modern times. Battery electric buses are being deployed worldwide, marking a change in public transport planning and operations. The emergence of fast and ultra-fast wireless charging for electric buses has br...

Urban communities should now build in specific measures, addressing multimodality and fair distribution of public space. The transformation of arterials into multimodal corridors can be a key strategy that will shape new futures. The social acceptance of “push” measure that aim to modify road space allocation have never been examined following quan...

Metro systems are critical public transport elements in several metropolitan areas around the world. Unexpected disruptions may undermine service provision of metro systems, and thus addressing their negative impacts is of primary importance. A first step towards developing mitigation measures involves the identification of those critical metro sta...

This study focuses on the concept of shared space, which encourage road users to share the same road space with little physical or visual separation. It contributes to defining traffic parameters in shared space network links by testing three hypotheses, a) high volume of bicycles and pedestrians (vulnerable road users VRUs) leads to higher traffic...

New transportation strategies, which aspire to create sustainable and resilient cities, prioritise active and public transport modes. Because these interventions have multiple effects, an integrated approach in planning became necessary. The aim of this paper is to determine transportation and land use impacts from active travel schemes using a Lan...

CERN, καθώς επίσης αξιολογεί ενδεχόμενες λύσεις για τη δημιουργία ενός βιώσιμου συστήματος μεταφορών για την κοινότητα του CERN. Για να αναλυθούν οι συνήθειες μετακίνησης και η ικανοποίηση των μελών της κοινότητας του CERN, αναπτύχθηκαν μοντέλα δηλωμένων και αποκαλυπτόμενων προτιμήσεων. Στη συνέχεια, δομήθηκαν και αξιολογήθηκαν διαφορετικές πολιτικ...

In an era of complexity, rapid technological advance and need for climate change action, urban roads may need to transform. The aim of this research is to identify the concepts underpinning the fundamental dimensions of the future urban road and open up an interdisciplinary dialogue about its delivery. We used a combinatorial approach incorporating...

E-scooters have emerged in recent years as an innovative and user-friendly transportation mode in urban areas worldwide. However, their incorporation in urban road networks is complex, since legal, social, and technical considerations often arise with respect to their usage. As official regulatory frameworks are often lacking, micromobility operato...

Recent advances in wireless communication technology allow for the cooperative coordination of vehicles and infrastructures under vehicle-to-everything (V2X) communication protocols. V2X communication protocols are shaping a new reality for intersection control, allowing for individual driver preferences to be taken into account, such as heterogene...

In complex urban road environments, where the safe movement of private cars has been consistentlyprioritized, new micro-mobility modes are introduced creating a road space allocation problem. Urbanand transport planners should answer an important dilemma: to share or segregate urban road space?Perceived safety is hypothesized to be a catalytic fact...

The taxi industry has changed dramatically during the last decade, as ride-sourcing applications, ride-sharing and alternative pricing schemes have emerged, either as complementing or competitive services and strategies. After some years of familiarity with such trends, it is interesting to explore where the taxi industry stands with respect to pos...

Over the last 10 years, transport policy experts are getting skeptical in regards to using each of traditional policy assessment methods, like Cost-Benefit Analysis (CBA), as the sole tool to evaluate transportation policies/projects. They argue that they do not provide any information regarding the distribution of policy effects across different p...

Battery Electric Vehicles (BEVs) have been in the market for over 10 years; however, their market diffusion has been slow despite their environmental and social advantages. Their high purchase cost is one of the most significant barriers towards their wider adoption. Policy makers have used the Total Cost of Ownership (TCO) estimate to expose the l...

Electric bus networks are steadily gaining ground as the prominent option for urban public transport. However, in contrast to conventional transit systems operated by diesel buses, electric bus networks are particularly vulnerable with respect to energy supply, both in terms of power level availability and the unobstructed access to charging points...

This paper models and investigates risk and security perception of metro travelers, in cases of malevolent, man-made incidents. Data is collected through an extensive survey in Athens, Greece; the survey includes an image-based stated-preference experiment, depicting different risk and security conditions. Econometric models are developed for estim...

The introduction of electric motor vehicles and the continuous research on automated vehicles introduces new features when evaluating and comparing their lifecycle costs to existing hybrid technologies. This study expands the traditional TCO value and integrates time costs to compare the performance of three different vehicle technologies: Hybrid E...

Either a result of inadequate supply or perceived high costs, illegal parking is an often-encountered phenomenon in urban areas worldwide and affects the performance and safety conditions of streets. In Greek cities in particular, illegal parking seems to be mostly observed when legal parking supply is limited, while at the same time, there is avai...

Advances in technology and alternative fuels change the on-road vehicle fleet mix, which traditionally depends on internal combustion vehicles. These changes affect also the total cost of ownership (TCO) per vehicle technology and their market penetration rates. The goal of this paper is to identify indicators for a TCO based analysis for three veh...

The purpose of this paper is to provide a methodological framework to identify traffic conditions based on non-calibrated video recordings captured from unmanned aerial vehicles (UAV) using deep learning. To this end, we propose two complementary to each other approaches: (i) identify in real time, with minimal computational cost, traffic condition...

Electrification of surface transportation networks has the potential to reduce oil consumption and transport-related emissions, with many relevant projects currently underway worldwide. Typically, transition to electric public transport services is gradual, as operators select specific lines to electrify during initial stages of electric vehicle de...

The COVID-19 outbreak led to significant changes in daily commuting. As lockdowns were imposed to metropolitan areas throughout the globe, travelers refrained heavily from using public transport, to maintain social distancing. Based on data from Athens, Greece, this paper investigates the anticipated, post-pandemic behavior of travelers with respec...

Continuous Approximation (CA) models have been used to solve transportation problems due to their ability to efficiently model complex transportation systems and offer flexibility in testing alternative policies. The current study develops a CA model for optimizing transportation planning for ferry services. The model is tested in a case study for...

The transformation of urban roadways into pedestrian streets is a popular measure for reshaping city parts and enhancing their livability. Nevertheless, pedestrianization schemes are expected to have some impact on the performance of the neighboring road network, especially if these are established ad-hoc or solely based on non-transport criteria....

Fare evasion is often encountered in public transport and results in severe revenue loss for operators. Using data from the Athens Metro system, this paper attempts to capture the extent of fare evasion, analyze its causes and identify attributes of passengers who practice fare evasion. Perceived effectiveness of measures that can restrict its prac...