Safety

User Acceptance and Public Perception Regarding Automated Driving Systems

Motamedi, Sanaz
Wang, Pei
Chan, Ching-Yao
2018

Fully Automated Driving System (ADS) is one of the most innovative and fundamentally disruptive changes in transportation. This technology has the potential to resolve or mitigate current transportation problems, including reducing traffic accidents, congestion, energy consumption, and pollution. However, the extent of these impacts will depend heavily on public perception and widespread adoption of ADSs. To gain a better understanding of user acceptance and public perception related to ADS, extensive interviews were conducted with Tesla end-users who have experience using partial ADS (i.e...

Understanding California wildfire evacuee behavior and joint choice making

Wong, Stephen D, PhD
Broader, Jacquelyn C
Walker, Joan L, PhD
Shaheen, Susan A, PhD
2022

For evacuations, people must make the critical decision to evacuate or stay followed by a multi-dimensional choice composed of concurrent decisions of their departure time, transportation mode, route, destination, and shelter type. These choices have important impacts on transportation response and evacuation outcomes. While extensive research has been conducted on hurricane evacuation behavior, little is known about wildfire evacuation behavior. To address this critical research gap, particularly related to joint choice-making in wildfires, we surveyed individuals impacted by the 2017...

Electric Bike Use in China and Their Impacts on the Environment, Safety, Mobility and Accessibility

Cherry, Christopher
2007

Chinese cities have a long legacy of bicycle use due to relatively low incomes, dense urban development, and short trip lengths. Because of tremendous economic growth resulting in increased motorization and spatial expansion of cities, trips are becoming longer and more difficult to make by bicycle. As a result, electric powered twowheelers have risen in popularity over the past five years. Touted as environmentally friendly vehicles, they are capable of traveling 450 kilometers on a single charge and emit zero tailpipe emissions. However, many cities are banning electric twowheelers from...

Managing Evacuation Routes

So, Stella K.
Daganzo, Carlos F.
2009

This paper shows that evacuation routes, such as a building’s stairwell or an urban freeway, may discharge inefficiently if left unmanaged, and that setting priority rules can speed up egress. Therefore, a simple control strategy is proposed. The strategy is decentralized and adaptive, based on readily available real-time data. The strategy is shown to be optimal in two senses: (i) it finishes the evacuation in the least possible time, and (ii) it evacuates the maximum number of people at all times. In both cases, it favors the people most at risk. The results shed light on other traffic...

On the perceptibility of safety systems

Grembek, Offer
Daganzo, Carlos F.
2010

The perceptibility of a safety system is defined as the extent to which the system can be perceived by the senses or the mind. The objective here is to study which safety systems are more easily perceived by the user and to identify design attributes that affect this level of perception. A web-based, pairwise comparison survey was conducted to evaluate the perceptibility of fifteen safety systems ranging from traffic safety systems to consumer safety. The analytic hierarchy process was applied to estimate the perceptibility levels and rank the safety systems. The results show that...

Strategies for Mitigating Impacts of Near-Side Bus Stops on Cars

Gu, Weihua
Cassidy, Michael J.
Gayah, Vikash V.
Ouyang, Yanfeng
2012

"Near-side stops" are bus stops located a short distance upstream of a signalized intersection. A bus dwelling at a near-side stop can impede queued cars upstream as they discharge during their green time at the intersection. Added car delays and residual queues can result. All else equal, the closer the stop’s location to the intersection, the greater the potential damage to car traffic. Models for locating these near-side stops to achieve target levels of residual queueing among cars are formulated using kinematic wave theory. This same approach was also used to develop a strategy for...

A Comparative Analysis of Pedestrian and Bicyclist Safety Around University Campuses

Grembek, Offer
Medury, Aditya
Orrick, Phyllis
Leung, Katherine
Ragland, David R.
Loukaitou-Sideris, Anastasia
Fink, Camille
Resnick, Justin
Wong, Norman
Shafizadeh, Kevan
Khan, Ghazan
2014

Large college campuses generate considerable volumes of traffic in a variety of modes, and in greater numbers, than found in most U.S. settings. This setting presents a unique study opportunity, as well as a significant potential for conflicts between motorized and non-motorized users of the transportation system, surrounded as most campuses are by mixed-use environments e.g. retail, restaurant, entertainment and high-density residential facilities such as apartments and dorms. At the same time, university campuses are also typically characterized by a central core area where most trips...

The Continuing Debate about Safety in Numbers—Data From Oakland, CA

Geyer, Judy
Raford, Noah
Ragland, David
Pham, Trinh
2005

The primary objective of this paper is to review the appropriate use of ratio variables in the study of pedestrian injury exposure. We provide a discussion that rejects the assumption that the relationship between a random variable (e.g., a population X) and a ratio (e.g., injury or disease per population Y/X) is necessarily negative. In the study of pedestrian risk, the null hypothesis is that pedestrian injury risk is constant with respect to pedestrian volume. This study employs a unique data set containing the number of pedestrian collisions, average annual pedestrian volume, average...

Safe Routes to School Safety and Mobility Analysis

Orenstein, Marla R.
Gutierrez, Nicolas
Rice, Thomas M.
Cooper, Jill F.
Ragland, David R.
2007

This report evaluates the SR2S program for a number of mandated issues: (i) The effectiveness of the program in reducing crashes, injuries and fatalities involving children in the vicinity of the projects; (ii) The impact of the program on levels of walking and bicycling to school; and (iii) The safety benefits of the program in comparison with other highway safety programs.

Space Syntax: An Innovative Pedestrian Volume Modeling Tool for Pedestrian Safety

Raford, Noah
Ragland, David R.
2003

This paper describes an innovative pedestrian modeling technique known as Space Syntax, which was used to create estimates of pedestrian volumes for the city of Oakland, California. These estimates were used to calculate pedestrian exposure rates and to create a Relative Risk Index for the city’s first pedestrian master plan. A major challenge facing planners, transportation engineers, and pedestrian-safety advocates is the lack of detailed and high quality pedestrian-exposure data. Exposure is defined as the rate of contact with a potentially harmful agent or event. Pedestrian exposure is...