Cyclist Stress and Biometric Sensing in Naturalistic Cycling

Cycling is gaining traction in the United States as a mode of transportation due to its plethora of benefits. However, cycling still makes up a very low percentage of modal share. One major hurdle to increased cycling modal share is that people feel cycling is unsafe and stressful. Many studies have considered cyclists’ stress, but these studies have not allowed participants to self-define their stressors during a cycling experience. This dissertation fills this gap by combining in-ride, open-ended surveys/interviews with naturalistic cycling methods. Cyclists wore eye tracking glasses and rode instrumented bicycles equipped with GPS and LiDAR to allow researchers to gain a deeper knowledge of their surroundings and reaction to them. This dissertation uses different combinations of sensors and survey techniques to explore cyclists’ stress and demonstrate the value of these methods. The first study uses in-ride surveys and instrumented bicycle data to explore the top causes of cyclists’ stress in an emerging and an established cycling city. The second study uses eye tracking glasses and survey techniques to better understand cyclists’ gaze behavior with varying stress, complexity, and stated skill. The last study uses eye tracking and survey techniques as well but uses them to give practical guidance for cyclist-focused pavement asset management. Various data analysis methods are used to assess these data individually and in combination including thematic analysis, GPS analysis, exploratory eye tracking measures, frame-by-frame video analysis, descriptive, and inferential statistics. These studies demonstrate that cyclists prefer separated infrastructure with smooth pavements. Although there were some differences by location or rider characteristics, the preferences for separated, smooth facilities are largely universal among cyclists. Although what caused cyclists stress was mostly consistent, gaze behavior did change with stated skill in unexpected ways demonstrating that researchers cannot assume cyclists’ gaze behavior will match what is known about drivers’ gaze behavior. These findings can contribute to bike infrastructure design and maintenance and the methods have opened the door to plenty of opportunity for future research into cyclist and other road user behavior.Ph.D

A sustainable and cost-effective pavement preservation method: Micro-milling and thin overlay, performance studies with 3d sensing

This thesis quantifies the performance of a pavement preservation treatment entitled micro-milling and thin overlay and improves rapid 3D data collection for the associated quality control measure, RVD. This is accomplished through performance analysis using both GDOT manual survey data and 3D data. The analysis showed that micro-milling and thin overlay has a similar performance to its comparable treatment, conventional milling. A life cycle cost analysis considering the construction and materials costs was also performed which showed that micro-milling could save over $500 million per year on the interstate system in Georgia when chosen instead of conventional milling. The life cycle assessment showed that it can also reduce energy usage by 61.9%, water usage by 61.8%, and carbon dioxide emissions by 61.7% as compared to conventional milling. A code for calculating RVD was refined and initial assessments of the effectiveness of the quality control measure showed that it was effective based on the existing data and that high RVD may be associated with raveling. The contributions of this thesis include quantifications of the performance of the method and improvement of the 3D data collection of the quality control measure. Together these can aid decision makers in making more effective and sustainable decisions for their pavement maintenance needs.M.S

Technology Review and Roadmap for Inventorying Complete Streets for Integration into Pavement Asset Management Systems

Complete Streets provide mobility for all modes of transportation including active transportation. Complete Streets are being implemented in the US and transportation agencies must maintain these assets, which requires bringing them into asset management systems. Many gaps exist to include Complete Streets in asset management, and there is no comprehensive plan for filling those gaps. This project developed a road map to fill those gaps. To create this roadmap, the study completed the following tasks: 1) develop and refine a survey 2) perform national and in-depth surveys, 3) synthesize survey outcomes, 4) identify current statuses, challenges, and needs, and 5) develop a roadmap for Complete Streets asset management. All 50 state Department of Transportations participated in the national survey while Caltrans, Georgia DOT, and the Atlanta and Washoe County Metropolitan Planning Organizations contributed to the in-depth survey. This repot synthesizes the outcomes of the surveys and literature review. The survey results showed that many agencies have some Complete Streets guidance (39/50), but far less have a dedicated liaison or office (15/40), and only seven agencies have Complete Streets performance measures. The three primary challenges are: 1) inadequate funding related to organizational structure 2) the need for a rating system, and 3) the need for improved data accessibility, collection methods, and management techniques. The proposed roadmap includes asset management development and improved data collection and analysis pathways. The roadmap is intended to be used as a starting point for the incorporation of Complete Streets into asset management.View the NCST Project Webpag

A Roadmap for Integrating Complete Streets Infrastructure into Pavement Asset Management Systems

Transportation agencies nationwide use pavement management systems (PMS) to maintain roads and highways. Pavement management has typically been used for auto-oriented infrastructure. However, state and local agencies are increasingly adopting complete streets policies to promote roadway designs focused on the needs of all transportation users. Complete streets designs include new assets such as pedestrian and bicycling infrastructure that are not typically incorporated into mainstream pavement management systems and do not have asset management systems of their own. Including pedestrian and bicycling features into asset management systems (directly in PMS or via other approaches) would help ensure that sidewalks and bike lanes are properly maintained over time and continue to provide the safety, environmental, and public health benefits attributed to complete streets design. Researchers at the Georgia Institute of Technology and the University of California, Davis surveyed all 50 state departments of transportation and conducted in-depth interviews with agency experts to understand the implementation status of complete streets asset management, identify what state transportation agencies need to improve their asset management plans, and develop a road map for implementing complete streets asset management. This policy brief summarizes the findings from that research and provides policy implications. View the NCST Project Webpag

An international comparison of the self-reported causes of cyclist stress using quasi-naturalistic cycling

This study explores the influences of attitudes and setting on cyclists' stated causes of stress using survey techniques and quasi-naturalistic cycling in both Delft, The Netherlands and Atlanta, Georgia, USA. The study recruited 28 participants in Delft and 41 in Atlanta. Participants cycled approximately 30 min on specified routes in both cities on an instrumented bicycle. Prior to cycling, the participants filled in a written survey about their cycling habits, attitudes, and demographics. At specified points during and after the ride, participants were interviewed about their stress levels throughout the ride and the causes of those stress levels. Thematic analysis and statistical methods are used to understand the interactions of setting (country), attitudes, stated stress, and sensor data. The top three stressors were motor vehicles, pavement, and poor infrastructure; 83% of participants mentioned a motor vehicle causing stress, 64% mentioned road surface, and 58% mentioned infrastructure. The results confirm the importance of motor vehicle interaction to cyclist stress, but also highlight some new insights on stress such as the importance of pavement condition. Speed differentials between cyclists and vehicles were also shown to be important and suggested cyclists in Delft felt comfortable to travel their ideal speed. This speed preference was supported by GPS data that showed the cyclists in Delft were cycling at speeds about half (12 kph) that of the cyclists in Atlanta (24 kph). Review of close-pass events demonstrated that cyclists in Delft were more comfortable with closer passes which could be associated with their belief that motorists notice them and/or speed differences between the vehicle and bicycle. The results also suggest that number of vehicle travel lanes can have mixed impacts on cyclist stress. These findings can be taken into consideration when designing bicycle facilities to create low-stress cycling networks.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin

The Influence of Situational Complexity, Stress, and Stated Skill on Cyclist Gaze Behaviour

Transport and Plannin

A Roadmap for Integrating Complete Streets Infrastructure into Pavement Asset Management Systems [Policy Brief]

Caltrans 65A0686 Task Order 028USDOT 69A35517471Transportation agencies nationwide use pavement management systems (PMS) to maintain roads and highways. Pavement management has typically been used for auto-oriented infrastructure. However, state and local agencies are increasingly adopting complete streets policies to promote roadway designs focused on the needs of all transportation users. Complete streets designs include new assets such as pedestrian and bicycling infrastructure that are not typically incorporated into mainstream pavement management systems and do not have asset management systems of their own. Including pedestrian and bicycling features into asset management systems (directly in PMS or via other approaches) would help ensure that sidewalks and bike lanes are properly maintained over time and continue to provide the safety, environmental, and public health benefits attributed to complete streets design. Researchers at the Georgia Institute of Technology and the University of California, Davis surveyed all 50 state departments of transportation and conducted in-depth interviews with agency experts to understand the implementation status of complete streets asset management, identify what state transportation agencies need to improve their asset management plans, and develop a road map for implementing complete streets asset management. This policy brief summarizes the findings from that research and provides policy implications