Apostolos Ziakopoulos

National Technical University of Athens | NTUA · Department of Transportation Planning

Within the SHOW project (GA No 875530), real-life urban demonstrations across 22 cities were conducted, exploring and validating the integration of Cooperative Connected and Automated Mobility (CCAM) in various public transport schemes. The project employs extensive traffic simulations using different tools and approaches. This chapter outlines the...

We recommend providing state-supported financial incentives and benefits for vehicle insurance policies using telematics. To achieve this policy recommendation, we propose the following: (1) Provision for financial incentives and benefits by the state for vehicle insurance policies using telematics across the European Union member states; (2) Condu...

The widespread adoption of Connected and Automated Vehicles (CAVs) is being propelled, not only in the realm of private vehicles but also within transit systems. This development serves to enhance urban transport activities, rendering transportation more appealing to passengers. The present study aims to identify and examine the safety effects of t...

The present research investigates a range of factors affecting autonomous vehicle (AV) acceptance of Greek citizens through a questionnaire distributed to 563 respondents. Following the extraction of descriptive statistics, self-organizing maps (SOMs) were employed to meaningfully categorize and aggregate questions pertaining to four main pillars o...

Background Globally, more than 322 million people are living with depression, with a considerable percentage driving while under the effects of such impairments. Their impacts on specific parameters of driver behavior and road safety, such as driver speed and reaction time, however, remain understudied. The literature indicates that driving perform...

This paper tries to identify and investigate the most significant factors that influenced the relationship between COVID-19 pandemic metrics (i.e., COVID-19 cases, fatalities, and reproduction rate) and restrictions (i.e., stringency index and lockdown measures) with driving behavior in the entire year 2020. To that aim, naturalistic driving data f...

Motorways are typically the safest road environment in terms of injury crashes per million vehicle kilometres; however, given the high severity of crashes occurring therein, there is still space for road safety improvements. The objective of this study is to compare the classification performance of five machine learning techniques for predictions...

Historical road crash data are the main indicator for measuring road safety outcomes. Over the past few decades, significant efforts have been made in obtaining and exploiting Surrogate Safety Measures (SSMs). SSMs have the potential to provide excellent sustainable road safety indicators and proxy measurements which can complement traditional hist...

Safety evaluation is a critical aspect through the future stages of automation development. Since there is a lack of historical and generalizable safety data in high levels of Connected and Autonomous Vehicles (CAVs), a possible approach to follow is the microscopic simulation method. Through microsimulation, vehicle trajectories are able to be exp...

High quality data on road crashes, road design characteristics, and traffic are typically required to predict crash frequency. Surrogate Safety Measures (SSMs) are an alternative category of indicators that can be used in road safety analyses in order to quantify various unsafe traffic events. The objective of this research is to exploit road geome...

While driver distraction remains an issue in modernized societies, technological advancements in data collection, storage and analysis provide the means for deeper insights of this complex phenomenon. In this research, factors influencing when driver distraction through mobile phone use occurs during naturalistic driving are investigated. Naturalis...

In recent decades, remarkable improvements in road safety have been achieved in the form of reductions of crash numbers. However, the improvement of vulnerable road users' safe mobility has not been as consistent, especially for pedestrians. The objective of this research is to examine the relationship of pedestrian safety attitudes and self-declar...

In contemporary motorized societies, human factors remain overwhelmingly responsible for road crash occurrence. Urged by considerable technological developments, insurers have integrated telematics to their operations to develop an array of Usage-Based-Insurance (UBI) schemes. The aim of the present research is to expand on the aforementioned topic...

Introduction In the unprecedented year of 2020, the rapid spread of COVID-19 disrupted everyday activities worldwide, leading the majority of countries to impose lockdowns and confine citizens in order to minimize the exponential increase in cases and casualties. To date, very few studies have been concerned with the effect of the pandemic on drivi...

The first half of the chapter a selective examination of several advancements in smart infrastructure, which can lead the transformation of the road networks to become more smart, green, efficient, safe and resilient. An array of innovative solutions exist today that are readily implementable and can lead to reductions in emissions, delay times, en...

This paper tries to identify and investigate the most significant factors that influenced the relationship between COVID-19 pandemic metrics (i.e., COVID-19 cases, fatalities and reproduction rate) and restrictions (i.e., stringency index and lockdown measures) with driving behavior in the entire 2020. To that aim, naturalistic driving data for a 1...

Harsh driving behavior events, such as harsh braking events (HBs) are road safety surrogate measures showing promising research venues towards crash mitigation, such as safety evaluations based on high-resolution driving data from smartphone sensors. This research presents a framework for aggregation and modelling of such data to highlight safety c...

In the maritime industry, more accurate predictions of fuel oil consumption (FOC) could yield multidimensional results including more precise bunker calculations, emission reductions, more informed planning and limiting operational costs. However, models often require sophisticated data that may be partially unavailable to operators beforehand. The...

Driving while fatigued is a considerably understudied risk factor contributing to car crashes every year. The first step in mitigating the respective crash risks is to attempt to infer fatigued driving from other parameters, in order to gauge its extend in road networks. The aim of this study is to investigate the extent to which declared fatigued...

Autonomous point to point shuttles are an emerging paradigm of a future mobility-on-demand ecosystem. However, the traffic and environmental impacts of their operation are largely under researched especially in relation to influential infrastructure related factors and service-related specifications. The scope of this study is to reveal the factors...

The Internet of Things (IoT) constantly offers new opportunities and features to monitor and analyze driver behavior through wide use of smartphones, effective data collection and Big Data analysis, resulting in assessment and improvement of driver behavior and safety. The objective of the present study is to investigate the impact of detailed trip...

The aim of the present study is to conduct spatial analysis of harsh events of driving behavior across road segments of an urban road network. The adopted approach involved automating the segment characteristic extraction process for the urban network study area. Subsequently, naturalistic driving big data from an innovative smartphone application...

Powered Two-Wheeler (PTW) riders constitute a very vulnerable group of road users, while riding a PTW is considerably more dangerous than using any other motor vehicle. Behavioral issues have been identified major moderating factors to PTW crashes, as riders display great variability in their attitudes towards road safety. Τhe aim of this paper is...

Objective The objective of the present study is twofold: (i) to explore the riding behavior of motorcyclists while speeding, based on detailed riding analytics collected by smartphone sensors, and (ii) to investigate whether personalized feedback can improve motorcyclist behavior. Methods In order to achieve the objective, a naturalistic riding ex...

Introduction Pedestrians are vulnerable road users exposed at risk during their interaction with vehicles in uncontrolled urban areas. In this paper, a critical overview of the literature and meta-analyses were conducted on the topic of pedestrian gap acceptance choice during midblock street crossings. Method Α large number of studies examining pe...

Driving under the influence of alcohol, drugs and fatigue are all important factors of crash causation. Exploring the link between driver attitudes and crash involvement provides understanding on these important issues. To that end, questionnaire answers of car drivers disclosing their attitudes on the impacts of driving under the influence of alco...

Introduction: COVID-19 has disrupted daily life and societal flow globally since December 2019; it introduced measures such as lockdown and suspension of all non-essential movements. As a result, driving activity was also significantly affected. Still, to-date, a quantitative assessment of the effect of COVID-19 on driving behavior during the lock...

Introduction: The number of road fatalities have been falling throughout the European Union (EU) over the past 20 years and most Member States have achieved an overall reduction. Research has mainly focused on protecting car occupants, with car occupant fatalities reducing significantly. However, recently there has been a plateauing in fatalities...

Research regarding the impact of traffic flow on road safety is a concept of critical importance. The topic of traffic flow and the various respective ways of handling and analyzing it has been the focus of intense research over the years. Hence, this chapter provides an overview of current knowledge regarding the analyses and impacts of traffic fl...

Planning of horizontal transport is a significant problem with material impact on the development budget and productivity of a container terminal. This contribution uses Queuing Theory, Petri Networks and Discrete Event Simulation to address the fleet size determination problem for tactical planning. Considering the different information and modell...

The objective of this research is to exploit high resolution driving behavior data collected via sensors of smartphones from 303 drivers in order to examine driver behavior at road segment and junction level. These sensor data are combined with traffic and road geometry characteristics and subsequently depicted spatially using Geographical Informat...

The main objective of this PhD Dissertation is the spatial analysis of harsh event frequencies in road segments using multi-parametric data, including (i) high resolution naturalistic driving and driver behavior data from smartphone sensors, (ii) microscopic road segment geometry and road network characteristic data from digital maps and (iii) high...

In road safety studies, spatial analyses are often implemented in order to reveal patterns of spatial variation and to examine the presence of spatial autocorrelation in road crash occurrences. Spatial analyses frequently employ exposure parameters in order to allow for comparisons between models. In this paper, meta-regression techniques are appli...

Advanced vehicle automation and the incorporation of more digital technologies in the task of driving, bring about new challenges in terms of the operator/vehicle/environment framework, where human factors play a crucial role. This paper attempts to consolidate the state-of-the-art in driver state measuring, as well as the corresponding technologie...

Introduction: Technological advancements during recent decades have led to the development of a wide array of tools and methods in order to record driving behavior and measure various aspects of driving performance. The aim of the present study is to present and comparatively assess the various driver recording tools that researchers have at their...

Economic evaluations of road safety measures are only rarely published in the scholarly literature. We collected and (re-)analyzed evidence in order to conduct cost-benefit analyses (CBAs) for 29 road safety measures. The information on crash costs was based on data from a survey in European countries. We applied a systematic procedure including co...

Spatial analyses of crashes have been adopted in road safety for decades in order to determine how crashes are affected by neighboring locations, how the influence of parameters varies spatially and which locations warrant interventions more urgently. The aim of the present research is to critically review the existing literature on different spati...

The objective of this paper is the review and comparative assessment of infrastructure related crash risk factors, with the explicit purpose of ranking them based on how detrimental they are towards road safety (i.e. crash risk, frequency and severity). This analysis was carried out within the SafetyCube project, which aimed to identify and quantif...

This study aims to estimate the overall impact of distraction due to operating in-vehicle information systems (IVIS) and similar devices while driving on road crashes. While similar research has been undertaken investigating the issue, varying results have been reported so far. Therefore a two-step approach was adopted: initially a review of the li...

The objective of this study is the investigation of the effect of tourism on road crashes. For this purpose, police data on road crashes in Greece for the 5-year period of 2011 to 2015 were collected by the research team and subsequently underwent processing to locate the contributing factors that characterize road crashes, that is, the nationality...

Currently studies exploring the effect of real-time traffic and weather characteristics on crash severity are relatively limited, and studies focusing on powered two-wheelers (PTWs) are even fewer. The objective of this paper is to add to current knowledge through the investigation of PTW occupant injury severity on the urban motorway Attica Tollwa...

Introduction: Conversation and other interactions with passengers while driving induce a level of distraction to the person driving. Method: This paper conducts a qualitative literature review on the effect of passenger interaction on road safety and then extends it by using meta-analysis techniques. Results: The literature review indicates th...

The objective of the present study is to provide an overview of the effects of selected Advanced Driver Assistance systems (ADAS), namely intelligent speed adaptation, collision warning and alcolock on driving behaviour and road safety. The methodology, developed within the SafetyCube project, was implemented in that purpose. International publishe...

There is strong evidence that work zones pose increased risk of crashes and injuries. The two most common risk factors associated with increased crash frequencies are work zone duration and length. However, relevant research on the topic is relatively limited. For that reason, this paper presents formal meta-analyses of studies that have estimated...

The objective of this study is to investigate road accident severity and likelihood in urban areas by analyzing real-time traffic data. In order to achieve the objective of the study, road accident data from a main road axis in Athens, Greece, were collected for the period 2006-2010. Subsequently, traffic data measured real-time were obtained from...