scholarly journals Towards a Sustainable City for Cyclists: Promoting Safety through a Mobile Sensing Application

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2116
Author(s):  
Pablo Boronat ◽  
Miguel Pérez-Francisco ◽  
Carlos T. Calafate ◽  
Juan-Carlos Cano
Keyword(s):  
Traffic Congestion ◽  
Response Times ◽  
Mobile Sensing ◽  
Environmental Footprint ◽  
Alert System ◽  
Sustainable City ◽  
Road Users ◽  
Vulnerable Road Users ◽  
4G Cellular Networks ◽  
Better Than

Riding a bicycle is a great manner to contribute to the preservation of our ecosystem. Cycling helps to reduce air pollution and traffic congestion, and so, it is one of the simplest ways to lower the environmental footprint of people. However, the cohabitation of cars and vulnerable road users, such as bikes, scooters, or pedestrians, is prone to cause accidents with serious consequences. In this context, technological solutions are sought that enable the generation of alerts to prevent these accidents, thereby promoting a safer city for these road users, and a cleaner environment. Alert systems based on smartphones can alleviate these situations since nearly all people carry such a device while traveling. In this work, we test the suitability of a smartphone based alert system, determining the most adequate communications architecture. Two protocols have been designed to send position and alert messages to/from a centralized server over 4G cellular networks. One of the protocols is implemented using a REST architecture on top of the HTTP protocol, and the other one is implemented over the UDP protocol. We show that the proposed alarm system is feasible regarding communication response time, and we conclude that the application should be implemented over the UDP protocol, as response times are about three times better than for the REST implementation. We tested the applications in real deployments, finding that drivers are warned of the presence of bicycles when closer than 150 m, having enough time to pay attention to the situation and drive more carefully to avoid a collision.

Bi-static Reflectivity Patterns of Vulnerable Road Users in the C-V2X Frequency Range

2020 ◽  
Author(s):  
Andreas Schwind ◽  
Willi Hofmann ◽  
Sreehari Buddappagari ◽  
Ralf Stephan ◽  
Reiner S. Thoma ◽  
...  
Keyword(s):  
Frequency Range ◽  
Road Users ◽  
Vulnerable Road Users

scholarly journals Predicting Motion of Vulnerable Road Users using High-Definition Maps and Efficient ConvNets

2020 ◽  
Author(s):  
Fang-Chieh Chou ◽  
Tsung-Han Lin ◽  
Henggang Cui ◽  
Vladan Radosavljevic ◽  
Thi Nguyen ◽  
...  
Keyword(s):  
High Definition ◽  
Road Users ◽  
Vulnerable Road Users

scholarly journals Shining Light on Retroreflectivity: Perceived Brightness of Surfaces with Varying Reflective Properties

2020 ◽  
Vol 64 (1) ◽  
pp. 1815-1819
Author(s):  
Savana L. King ◽  
Ellen C. Szubski ◽  
Richard A. Tyrrell
Keyword(s):  
Entrance Angle ◽  
Road Signs ◽  
Road Users ◽  
Vulnerable Road Users

Typical road users appear not to understand retroreflectivity despite nightly exposure to retroreflective materials like road signs. A critical benefit of retroreflective materials is a robustness to changes in entrance angle, the angle at which light strikes the material. This study aims to measure observers’ perceived brightness judgments of surfaces representing three types of reflection (diffuse, specular, and retroreflective) when viewed under manipulations of entrance angle. Perceived brightness will be assessed before and during a demonstration including illumination from a source positioned near the observer’s eyes. Prior to the demonstration, observers are hypothesized to predict specular and retroreflective surfaces will have a consistent brightness despite changes in entrance angle. Seeing the retroreflectivity demo is expected to result in increased perceived brightness of only the retroreflective surfaces in the more extreme entrance angle conditions. Watching visual demonstrations of reflection, however, is expected to produce an enhanced appreciation that retroreflective (but not specular or diffuse) surfaces remain bright despite large changes in entrance angle. This evidence may eventually increase demand for retroreflective markings by vulnerable road users.

scholarly journals Autonomous Vehicles and Vulnerable Road-Users—Important Considerations and Requirements Based on Crash Data from Two Countries

2021 ◽  
Vol 11 (7) ◽  
pp. 101
Author(s):  
Andrew Paul Morris ◽  
Narelle Haworth ◽  
Ashleigh Filtness ◽  
Daryl-Palma Asongu Nguatem ◽  
Laurie Brown ◽  
...  
Keyword(s):  
Autonomous Vehicles ◽  
Red Light ◽  
Road User ◽  
Red Light Running ◽  
Crash Data ◽  
Passenger Vehicles ◽  
Road Users ◽  
Vulnerable Road User ◽  
Vulnerable Road Users ◽  
Road Intersections

(1) Background: Passenger vehicles equipped with advanced driver-assistance system (ADAS) functionalities are becoming more prevalent within vehicle fleets. However, the full effects of offering such systems, which may allow for drivers to become less than 100% engaged with the task of driving, may have detrimental impacts on other road-users, particularly vulnerable road-users, for a variety of reasons. (2) Crash data were analysed in two countries (Great Britain and Australia) to examine some challenging traffic scenarios that are prevalent in both countries and represent scenarios in which future connected and autonomous vehicles may be challenged in terms of safe manoeuvring. (3) Road intersections are currently very common locations for vulnerable road-user accidents; traffic flows and road-user behaviours at intersections can be unpredictable, with many vehicles behaving inconsistently (e.g., red-light running and failure to stop or give way), and many vulnerable road-users taking unforeseen risks. (4) Conclusions: The challenges of unpredictable vulnerable road-user behaviour at intersections (including road-users violating traffic or safe-crossing signals, or taking other risks) combined with the lack of knowledge of CAV responses to intersection rules, could be problematic. This could be further compounded by changes to nonverbal communication that currently exist between road-users, which could become more challenging once CAVs become more widespread.

scholarly journals Impact of External Human–Machine Interface Communication Strategies of Automated Vehicles on Pedestrians’ Crossing Decisions and Behaviors in an Urban Environment

2021 ◽  
Vol 13 (15) ◽  
pp. 8396
Author(s):  
Marc Wilbrink ◽  
Merle Lau ◽  
Johannes Illgner ◽  
Anna Schieben ◽  
Michael Oehl
Keyword(s):  
Urban Traffic ◽  
Automated Vehicles ◽  
Negative Effects ◽  
Communication Tools ◽  
Automated Vehicle ◽  
Additional Information ◽  
Road Users ◽  
Vulnerable Road Users ◽  
And Behaviors ◽  
Vehicle Automation

The development of automated vehicles (AVs) and their integration into traffic are seen by many vehicle manufacturers and stakeholders such as cities or transportation companies as a revolution in mobility. In future urban traffic, it is more likely that AVs will operate not in separated traffic spaces but in so-called mixed traffic environments where different types of traffic participants interact. Therefore, AVs must be able to communicate with other traffic participants, e.g., pedestrians as vulnerable road users (VRUs), to solve ambiguous traffic situations. To achieve well-working communication and thereby safe interaction between AVs and other traffic participants, the latest research discusses external human–machine interfaces (eHMIs) as promising communication tools. Therefore, this study examines the potential positive and negative effects of AVs equipped with static (only displaying the current vehicle automation status (VAS)) and dynamic (communicating an AV’s perception and intention) eHMIs on the interaction with pedestrians by taking subjective and objective measurements into account. In a Virtual Reality (VR) simulator study, 62 participants were instructed to cross a street while interacting with non-automated (without eHMI) and automated vehicles (equipped with static eHMI or dynamic eHMI). The results reveal that a static eHMI had no effect on pedestrians’ crossing decisions and behaviors compared to a non-automated vehicle without any eHMI. However, participants benefit from the additional information of a dynamic eHMI by making earlier decisions to cross the street and higher certainties regarding their decisions when interacting with an AV with a dynamic eHMI compared to an AV with a static eHMI or a non-automated vehicle. Implications for a holistic evaluation of eHMIs as AV communication tools and their safe introduction into traffic are discussed based on the results.

scholarly journals Emergency presentations by vulnerable road users: implications for injury prevention

2006 ◽  
Vol 12 (1) ◽  
pp. 12-14 ◽  
Author(s):  
L B Meuleners ◽  
A H Lee ◽  
C Haworth
Keyword(s):  
Injury Prevention ◽  
Road Users ◽  
Vulnerable Road Users

Does crossing the road in a group influence pedestrians’ gaze behavior?

2020 ◽  
Vol 64 (1) ◽  
pp. 1938-1942
Author(s):  
Mirjam Lanzer ◽  
Martin Baumann
Keyword(s):  
Group Size ◽  
Situational Factors ◽  
Gaze Behavior ◽  
The Road ◽  
Road Users ◽  
Gender Influence ◽  
Vulnerable Road Users ◽  
Group Members ◽  
And Gender ◽  
Group Characteristics

So far, research on pedestrians’ gaze behavior while crossing roads has mainly focused on individual pedestrians rather than groups. However, pedestrians often travel in groups especially in downtown areas. This observational study investigated how group characteristics (group size and movement of the group), situational factors (presence of traffic), and demographic variables (age and gender) influence pedestrians’ gaze behavior towards traffic during road crossing. A total of N = 197 pedestrians were observed of whom n = 24 traveled alone, n = 128 traveled in groups of two or three, and n = 45 traveled in groups of four or more. Results indicated that with increasing group size, the odds to observe traffic decreased. Diffusion of responsibility among group members might explain this effect. Finally, pedestrians’ group characteristics should be considered when developing automated vehicles that interact with vulnerable road users.

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