Driver and Bicyclist Comprehension of Blue Light Detection Confirmation Systems

This study analyzed motorist and bicyclist understanding and preference of positive confirmation of detection of a bicycle by the traffic signal infrastructure using a blue light detection confirmation (BLDC). The research analyzed results of an online survey of 1,123 respondents and intercept survey of 337 respondents. The study initially found that participants of the survey did not understand the meaning of the blue light itself, but comprehension of the system rose from 40% to 50% when supplemental signs were used. Respondents overwhelmingly indicated that they preferred the sign option that included symbols, text, and a representation of the blue light, in comparison with the sign options that only included symbol and text, or text and blue dot. Additionally, respondents indicated that they “strongly agree” that the supplemental signage helped with understanding the purpose of the detection confirmation devices, that they would support the system at intersections, and that it made them feel better about waiting at an intersection with light. Including supplemental signage with the symbol, text, and blue dot could potentially improve the riding experience for users, as it was strongly preferred among the alternative sign options that were tested; however, further evaluation of sign configurations may be warranted

Measuring pedestrian level of stress in urban environments: Naturalistic walking pilot study

Walking is the most basic and sustainable mode of transportation, and many jurisdictions would like to see increased walking rates as a way of reducing congestion and emission levels and improving public health. In the United States, walking trips account for 10.5% of all trips undertaken. To increase this rate, additional research on what makes people feel more comfortable while walking is needed. Research on pedestrian quality of service (QOS) has sought to quantify the performance of the pedestrian facilities from a pedestrian’s perspective. However, the impact of pedestrian safety countermeasures on pedestrian QOS for roadway crossings is largely unknown. The objective of this study is to discern pedestrian QOS based on physiological measurements of pedestrians performing normal walking activities in different traffic contexts. The naturalistic walking study described in this paper recruited 15 pedestrians and asked each to wear an instrumented wristband and GPS recorder on all walking trips for one week. Surprisingly, the findings from the study showed no correlation between participants’ stress levels and individual crossing locations. Instead, stress was associated with roadway conditions. Higher levels of stress were generally associated with walking in proximity to collector and arterial streets and in areas with industrial and mixed (e.g., offices, retail, residential) land uses. Stress levels were tempered in lower-density residential land uses, as well as in forest, park, and university campus environments. The outcomes from this study can inform how planners design urban environments that reduce pedestrian stress levels to promote walkability

Developing and optimizing applications in Hadoop

This contribution is about sharing our recent experiences of building Hadoop based application. Hadoop ecosystem now offers myriad of tools which can overwhelm new users, yet there are successful ways these tools can be leveraged to solve problems. We look at factors to consider when using Hadoop to model and store data, best practices for moving data in and out of the system and common processing patterns, at each stage relating with the real world experience gained while developing such application. We share many of the design choices, tools developed and how to profile a distributed application which can be applied for other scenarios as well. In conclusion, the goal of the presentation is to provide guidance to architect Hadoop based application and share some of the reusable components developed in this process

Integration of Oracle and Hadoop: Hybrid databases affordable at scale

This work reports on the activities aimed at integrating Oracle and Hadoop technologies for the use cases of CERN database services and in particular on the development of solutions for offloading data and queries from Oracle databases into Hadoop-based systems. The goal and interest of this investigation is to increase the scalability and optimize the cost/performance footprint for some of our largest Oracle databases. These concepts have been applied, among others, to build offline copies of CERN accelerator controls and logging databases. The tested solution allows to run reports on the controls data offloaded in Hadoop without affecting the critical production database, providing both performance benefits and cost reduction for the underlying infrastructure. Other use cases discussed include building hybrid database solutions with Oracle and Hadoop, offering the combined advantages of a mature relational database system with a scalable analytics engine

User Comprehension of Bicycle Signal Countdown Timers

For a person on a bicycle at signalized intersections, trail crossings, or midblock locations, knowing how long they must wait to receive a green indication is valuable information. In the international context, this information is often provided by small, nearside bicycle signal heads that contain a countdown display that visually conveys the amount of waiting time. This paper presents the results of research to investigate the comprehension of bicycle countdown timer displays in the U.S. context. The study conducted an online survey to analyze the understanding and preference of three alternative bicycle countdown timer displays. Respondents were recruited by two recruitment methods: mailed postcards (568 responses) and social media ads (772 responses). A countdown timer with circular disappearing dots was then installed at an intersection in Portland, OR, and an intercept survey was conducted of users (29 responses). For both surveys, comprehension rates were established by coding an open-ended response to a question about the display\u27s intended meaning. The surveys found that the bicycle signal countdown displays were intuitive, and the intended meaning was fully understood by over 60% of online survey respondents and 52% of the intercepted bicyclists. Partial comprehension increased to over 70% and 97% of those intercepted, respectively, which would result in safe user interpretation. A countdown timer may also improve the waiting experience for stopped bicyclists, as 70% of respondents strongly or somewhat agreed that they would feel better about waiting at an intersection if a bicycle countdown timer was present