Mehmet Baran UlakUniversity of Twente | UT · Transportation Engineering and Management
Mehmet Baran Ulak
Ph.D.
About
50
Publications
10,185
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468
Citations
Citations since 2017
Introduction
My research interest is diverse and spans from transportation safety and accessibility to analysis of urban systems and spatial planning. Of the various subjects I am interested in various subjects and broad interdisciplinary areas including the statistical and spatial analysis of traffic safety, geographical aspects of safety and accessibility, and demographic and socioeconomic assessment of daily transportation incidents, intelligent transportation systems, and smart city concepts. I have also focused on the emergency disaster resilience for hurricanes. I have a particular curiosity about often disregarded importance and role of demographics and socioeconomics, or human element in general, in tackling transportation-related safety issues.
Additional affiliations
February 2019 - May 2020
January 2019 - February 2019
August 2014 - December 2019
Publications
Publications (50)
The 15 min city (or “X-minute city” in general) concept aims to give people access to all essential services and daily needs (e.g., healthcare, education, etc.) within X minutes of active transportation, to improve transport equity, sustainability, and traffic safety. To date, there is a lack of methods and tools to assess to what degree cities cur...
Accessibility, livability, and public health in urban areas can be improved by promoting sustainable and eco-friendly modes of transport such as rail transit. The success and feasibility of a rail transit system, however, rely on maintaining sufficient ridership depending on several factors. This study focuses on two of these factors in examining t...
New technologies are gaining ground in various disciplines, and road safety is not an exception. The objective of this paper is twofold: (1) to review the state-of-the-art technologies implemented in bicycles to improve cyclists’ safety, and (2) to propose a classification for the levels of smartness of emerging “smart bikes”. This paper defines si...
Cycling is promoted as a sustainable and healthy mode of transport, which results in an increase in bicycle use in urban areas. Increasing bicycle use comes with growing concerns about cyclist safety. This study examines how the temporal variation in the network-wide exposure to cyclists and motorised vehicles affects bicycle crash frequency. Netwo...
Built-environment factors potentially alleviate or aggravate traffic safety problems in urban areas. This paper aims to investigate the relationships of these factors with vehicle-bicycle and vehicle-vehicle property damage only (PDO) and killed and severe injury (KSI) crashes in urban areas. For this purpose, an area-level analysis using 100x100m²...
Over the last three decades, traffic crashes have been one of the leading causes of fatalities and economic losses in the U.S.; compared with other age groups, this is especially concerning for the youth population (those aged between 16 and 24), mostly due to their inexperience, greater inattentiveness, and riskier behavior while driving. This res...
This study investigates the impacts of the noticeable change in mobility during the COVID-19 pandemic with analyzing its impact on the spatiotemporal patterns of crashes in four demographically different counties in Florida. We employed three methods: (1) a Geographic Information System (GIS)-based method to visualize the spatial differences in cra...
Transportation systems are vulnerable to hurricanes and yet their recovery plays a critical role in returning a community to its pre-hurricane state. Vegetative debris is among the most significant causes of disruptions on transportation infrastructure. Therefore, identifying the driving factors of hurricane-caused debris generation can help clear...
Catastrophic weather has significantly battered the U.S. Gulf Coast in recent years and exposed critical deficiencies in the resilience across communities and organizations. These deficiencies compel the devising of strategies to identify critical infrastructure components that require more attention with regard to building resilience. This article...
Despite the decline in the numbers of crashes and fatalities in the U.S. since 1990, pedestrian crashes have been steadily increasing and reached its 28-year peak in 2018. This increase led to initiatives such as Vision-Zero in response to this deterioration in pedestrian safety. In spite of the severe outcomes of pedestrian crashes, guidelines are...
The alternative public transportation options such as subway, bus, or taxis compete with each other to attract passengers. The competition depends on many factors such as travel time, reliability and convenience. Convenience is a collection of attributes affecting the attractiveness of the service including access and egress easiness, service frequ...
To alleviate the impacts of freeway incidents and improve the traffic conditions on the entire transportation network, operational systems of discrete facilities need to be coordinated on a corridor. As such, this study focuses on a new traffic diversion methodology for a better utilization of the available traffic capacity of the corridor. The met...
Rail transit delays are generally discussed in terms of on-time performance or problems at individual stops. Such stop-scale approaches ignore the fact that delays are also caused and perpetuated by network-wide factors (e.g., bottlenecks caused by shared tracks by multiple transit lines). The objective of this paper is to develop a network model a...
![Fig. 2 -GLOSA algorithm flowchart (based on [12])](profile/Hasan-Karabag/publication/344203033/figure/fig1/AS:934572690784263@1599830901943/GLOSA-algorithm-flowchart-based-on-12_Q320.jpg)
U.S. Environmental Protection Agency (EPA) states that transportation is the second leading source for air pollution. Therefore, any improvement in transportation technology can bring substantial benefits by reducing the vehicle exhaust emissions. Recently, connected vehicle (CV) technologies have become increasingly popular since their penetration...
This paper provides a prescriptive resilience modelling framework for power grids that can account for the socio-demographic impacts of system improvements in the case of hurricanes. The power infrastructure failure rate and recovery duration models are developed based on Hurricane Hermine power outage data obtained from the City of Tallahassee, FL...
Conventional intersection designs are known to be problematic and unreliable when handling the complexity associated with the heavy traffic volume and travel demand on today’s roadways. Alternative innovative and safer designs such as the restricted crossing U-turn (RCUT) intersection can address these complex problems. However, there is still a ga...
Emergency shelters are essential to protect evacuees from any threats posed by a hurricane and provide them with basic needs and assistance until it is safe to return to their homes. In a posthurricane situation, existing critical infrastructure for emergency shelters is likely being challenged to its limits in response to growing evacuee needs. As...
This study examined the role of channel synchronicity (synchronous versus asynchronous) in shaping perceptions of citizens (n=467) of a mid-sized city in the Southeastern U.S. regarding the speed and quality of information received from their local government during and immediately after two hurricanes. We employed a mixed-methods approach combinin...
Hurricanes lead to substantial infrastructure system damages, such as roadway closures and power outages, in the US annually, especially in states like Florida. As such, this paper aimed to assess the impacts of Hurricane Hermine (2016) and Hurricane Michael (2018) on the City of Tallahassee, the capital of Florida, via exploratory spatial and stat...
This paper investigates the proximity of crashes to the residential locations of the crash occupants. To this end, two years of crash data was disaggregated by the crash occupants' ZIP codes for a study area in Southwest Florida in order to calculate the roadway network distances between their residential ZIP code area centroids (origins) and crash...
Identifying hotspots or crash clusters is an important problem for detecting high-risk locations at which vehicle accidents frequently occur. Several hotspot identification methods have been developed in the literature; however, there are often large differences between the spatial distributions of hotspots obtained by these methods, and spatial we...
Traffic safety and performance measures such as crash risk and queue lengths or travel times are influenced by several important factors including those related to environment, human, and roadway design, especially 2 at intersections. Previous research has studied different aspects related to these factors, yet these characteristics are not fully i...
This report is about the development of Safety Performance Functions (SPF) and Crash Modification Factors (CMF) for Restricted Crossing U-Turn (RCUT) intersections.
Resilience is mostly considered as a single dimension attribute of a system. Most of the recent works on resilience treat it as a single dimension attribute of a system or study the different dimensions of the resilience separately without considering its multi-domain nature. In this paper, we propose an advanced causal inference approach combined...
Over the years, as the roadway networks have been developing gradually to improve transportation accessibility to various facilities, the probability of traffic crash occurrences has also increased consequently. With an increasing transportation demand, the traffic safety needs to be improved in order to reduce the crash rates and the exposure of t...
The growth of metropolitan regions in the U.S. leads to transportation safety issues related to roadway crashes that imperil personal wellbeing. Previous studies have investigated the environmental, traffic, roadway, and human related factors that influence the frequency and severity of crashes, and focused on the spatial distribution of roadway cr...
Roadway closures magnify the adverse effects of disasters on people since any type of such disruption increases the emergency response travel time (ERTT), which is of central importance for the safety and survival of the affected people. Especially in the State of Florida, high winds due to hurricanes, such as the Hurricane Hermine, lead to notable...
The increase in 65 years and older population in the United States compels the investigation of the crashes
involving all aging (65+) roadway users (drivers, passengers, bicyclists, and pedestrians) in order to ensure their
safety. As such, the objective of this research is to provide a spatiotemporal comparative investigation of the
crashes involv...
Florida's emergency relief operations were significantly affected by recent hurricanes such as Hermine and Irma that caused massive roadway and power system distributions. During these recent devastating hurricanes, the problems associated with providing accessibility and safety became even more challenging, especially for those vulnerable communit...
Hurricane Hermine was the first hurricane to make landfall in Florida since Hurricane Wilma in 2005, and was the first hurricane to directly hit Apalachee Bay since Hurricane Alma in 1966. As a result, Hermine left 100,000 residents without power in the City of Tallahassee, the capital of Florida, knocking out trees, power lines and shutting down s...
State Departments of Transportation (DOT) utilize Twitter frequently in order to disseminate critical information regarding traffic conditions (e.g., accidents, roadway closures, and congestion) to public. Even though factors driving the effectiveness and reach of private social media accounts have been studied extensively in the literature, they a...
Natural disasters have devastating effects on the infrastructure and disrupt every aspect of daily life in the regions they hit. To alleviate problems caused by these disasters, first an impact assessment is needed. As such, this paper focuses on a two-step methodology to identify the impact of Hurricane Hermine on the City of Tallahassee, the capi...
Investigation of different gap acceptance models in accurately estimating critical gap
Roadway accidents claim more than 30,000 lives each year in the United States, and they continue adversely affecting people’s well-being. This problem becomes even more challenging when aging populations are considered due to their vulnerability to accidents. This is especially a major concern in Florida since the accident risk is increasing propor...
Previous studies have examined hospital accessibility issues, while other work has exhaustively investigated several aspects of roadway crashes such as their severity and frequency, possible causal factors, and their clustering on networks. However, the nature of the relationship between them, in terms of the accessibility of severe crash hotspots...
Traffic crashes imperil roadway users and impose a considerable economic burden on society. Previous studies have investigated several aspects of traffic crashes such as severity, frequency, and influential factors, yet the causal and spatial differences between crashes involving drivers from different age groups remain unclear. In this paper, we i...
This study attempts to understand the unique nature of crashes involving aging drivers, unlike many previous crash-focused traffic safety studies mostly focusing on the general population. The utmost importance is given to answering the following question: How do the crashes involving aging drivers vary compared to crashes involving other age group...
The amount of perishable products transported via the existing intermodal freight networks has significantly increased over the last years. Perishable products tend to decay due to a wide range of external factors. Supply chain operations mismanagement causes waste of substantial volumes of perishable products every year. The heretofore proposed ma...
This study deals with the effects of pore vapor pressure on concrete exposed to elevated temperatures. In order to comprehend these effects, experiments and numerical analyses were conducted. The main purpose was to evaluate tensile strength alteration caused by pore vapor pressure.
Traffic crashes are one of the leading causes of death, substantial economic loss, and severe injuries for the drivers. From a transportation safety perspective, this problem becomes even more challenging and complex when aging populations are considered due to their cognitive, behavioral, and health limitations. Since the growth among aging Florid...
Projects
Projects (4)
The overall goal of this project is to provide appropriate safety performance functions for different types of RCUT intersections for use by DOT planners and engineers at various levels of project development and safety analysis.
This study aims to examine the effect of vehicle operation mode on exhaust emission (for CO and NOx) by simulating the model in terms of hot & steady running and idling running. It is expected that major part of total vehicle emission can be mostly a result of frequently and/or sudden speed and acceleration & deceleration changes and/or roadway characteristics such as grade and/or load on vehicle etc.