Alex Bigazzi

The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.

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This thesis aims to inform fully autonomous self-driving vehicle (SDV) policy with respect to pedestrian comfort and safety. To pursue new insights, the novel approach of Structural Topic Modeling is used to organize open-response comments into prominent topics, or themes, and explore the factors affecting the prevalence and content of topics. This thesis is comprised of two parts. In both parts, participants in an online survey rated the comfort and safety of pedestrian interactions shown in short video clips and provided open-response comments clarifying their ratings. In part 1, the video clips showed pedestrian interactions with human-driven vehicles (HDVs) and bicycles. In Part 2, the video clips only showed interactions with HDVs, except participants were told that half of the videos involved SDVS. This deception-based survey design allowed for isolation of the intrinsic effect of SDV technology on comfort and safety perceptions across a broad sample of the population, separate from potential operating differences from HDVs. Results indicate that pedestrian interactions with each of the three types of road users were perceived as fundamentally different and should be treated as such in future research and analysis. Interactions with bicycles elicited topics mainly concerned with yielding; interactions with HDVs elicited topics mainly concerned with risk; and interactions with SDVs elicited topics mainly concerned with rule compliance. Participants increasingly ascribed more responsibility to the pedestrian as the degree of detachment (physically and conceptually) between the pedestrian and the interacting road user increased – from cyclist to HDV to SDV. To ensure that the integration of SDVs into the existing transportation system does not undermine efforts to prioritize and promote active transportation, SDVs should be programmed to strictly comply with road rules.

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Better understanding of the impacts of new mobility services (NMS) is needed to inform evidence-based policy, but cities and researchers are hindered by a lack of access to detailed system data. Application Programming Interface (API) services can be a medium for real-time data sharing and have been used for data collection in the past. However, the literature lacks a systematic examination of the potential value of publicly-available API data for extracting policy-relevant information, specifically supply and demand, on NMS. This thesis is comprised of two main parts. The objectives of part 1 are to catalogue all the publicly-available API data streams for NMS in three major cities known as the Cascadia Corridor (Vancouver, British Columbia, Seattle, Washington, and Portland, Oregon), to create, apply, and share web data extraction tools (Python scripts) for each API, and to assess the usefulness of the extracted data in quantifying supply and demand for each service. The objective of part 2 is to use the data extracted in part 1 to assess the equity performance of Uber’s wheelchair accessible service, UberWAV, by itself and in comparison to the standard Uber service, UberX. In part 2 the temporal and spatial distributions of the availability and accessibility of each service is investigated. Results of part 1 reveal some measures of supply and demand that can be extracted from API data and useful in future analysis. However, important information on supply and demand of most of the NMS in these cities cannot be obtained through API data extraction. Stronger open data policies for mobility services are therefore needed if policymakers want to obtain useful and independent insights on the usage of these services. Results of part 2 show that unlike UberX which is almost universally available, UberWAV is only available 60% of the time with an average wait time of 16 minutes on average (4 times that of UberX). The distributional analysis shows no inequitable distribution of availability or accessibility of UberWAV in Portland, Oregon with regards to income, and race. To make UberWAV more available and accessible, cities must enforce stronger licensing schemes to ridesourcing companies.

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No abstract available.

With an increasing focus on bicycling as a mode of urban transportation, there is a pressing need for advanced tools for bicycle travel analysis and modeling. The objective of this thesis is to introduce “Biking schedules” to represent archetypal urban cycling dynamics along with its methods of construction and potential applications.Biking schedules are constructed by appending short trip segments, called microtrips, together. Three different methods of constructing biking schedules with both speed and road grade attributes are developed. As an initial proof-of-concept, the methods are applied and compared using a pre-existing demonstration data set of 55 hours of 1-Hz on-road GPS data from three cyclists. Biking schedules are evaluated based on their ability to represent the speed dynamics, power output, and breathing rates of a calibration data set and then validated for different riders. The impact of using coarser 3, 5, and 10 second GPS logging intervals on the accuracy of the schedules is also evaluated. Results indicate that the best biking schedule construction method depends on the volume and resolution of the calibration data set. Overall, biking schedules can successfully represent most of the assessed characteristics of cycling dynamics in the calibration data set within 5%. As a second step, the biking schedule construction methods are further developed and validated by collecting and applying a large, naturalistic, GPS-based data set of 2314 bicycle trips in Vancouver, Canada. We specifically explored the optimal microtrip definition to be adopted in constructing biking schedules. The choice of the optimal microtrip definition depends on the parameter that biking schedules are originally generated to model. Generally, the 150m microtrips generated the most precise biking schedules. The collected data are also used to compare the travel characteristics and construct biking schedules for regular and electric bikes. Results show that electric bikes travel 7 km/hr and accelerate 0.17 km/hr/sec faster than regular bicycles. Moreover, the total energy used to move electric bikes is almost twice as much as the energy used by regular bikes. These results have implications in designing bike lanes and safety analysis. Potential applications for biking schedules are also discussed.

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Road grade is a major factor influencing cyclist physiology and travel decisions. Research studying cycling and other non-motorized transportation modes often use coarse elevation data sources to obtain the necessary grade information. In addition, routing applications such as Google Maps, Strava and RideWithGPS append the GPS data collected with elevation data from the coarse elevation datasets which can be inaccurate and inadequate. The objective of this research is to determine the best methods of obtaining road grade information on a network scale for bicycle travel analysis and to understand the limitations of the coarse data sources. Multiple elevation data sources, high resolution and coarse, are collected for the city of Vancouver, BC Canada. Different road grade estimation algorithms are then applied to the data sources at eight locations in the city where ground truth elevation data were surveyed using a total station. Different cycling performance measures were used to compare the elevation and road grade estimates of the locations to identify the data sources that accurately represent the true ground elevation for cycling analysis. Finally, the elevated structures in the City of Vancouver are characterized to help infer grade information in the absence of high resolution data sources.Results show that elevation data collected from Light Detection and Ranging (LiDAR) are the most accurate for elevated and non-elevated roads with mean absolute error in the elevation not exceeding 0.6 meters. Additionally, road grades derived from LiDAR data sources were closest to measured grade data. In the absence of LiDAR, coarse data sources can provide adequate grade estimates for cycling analysis on non-elevated structures. However, on elevated structures, especially ones without a single dominant grade, coarse datasets can only provide estimates of total elevation change or mean grade. Overall, the results show that it is vital to understand the accuracy and limitations of elevation data sources used in analysis and modeling of active travel.

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Urban cyclist’s physical characteristics are important for advanced modelling of bicycle speed and energy expenditure, with applications including infrastructure design, network analysis, and health and safety assessments. However, representative values for diverse urban travellers have not been established. This study investigates the physical characteristics of real-world urban cyclists, including rolling and drag resistance parameters, and bicycle and cargo masses. Relationships among physical characteristics socio-demographics and travel behaviour are also analysed, and a bicycle cruising speed model is derived to illustrate usefulness of the sought parameters.Firstly, a 12-sensor, 100-meter coast-down test setup is developed and indoor and outdoor validation tests are performed. Outdoor validation tests generate rolling resistance coefficient estimates of 0.0064 ±0.0013 and effective frontal area estimates of 0.63 ±0.11 m².Secondly, resistance parameters were measured utilizing the novel coast-down test for 557 intercepted cyclists in Vancouver, Canada.. The average (standard deviation) of coefficient of rolling resistance (??), effective frontal area (????), bicycle plus cargo mass, and bicycle-only mass were 0.0077 (0.0036), 0.559 (0.170) m², 18.3 (4.1) kg, and 13.7 (3.3) kg, respectively. The range of measured values is wider and higher than suggested in the literature.Thirdly, the sample of intercepted cyclists is categorised based on observed physical attributes of the bicycle and rider. Three typologies defined through cluster analysis were identified as Road (R), Hybrid (H) and Mountain (M) style urban cyclists. The analysis indicates that cycling efficiency, perceptions, preferences, and habits are related to physical typology in a complex but consistent manner. M, H, and R cyclists are, in that order, increasingly more efficient, more comfortable in mixed traffic, moreIIconsistently year-round cyclists, self-reportedly faster, and engage in more physical activity. Physical typologies might help unveil new motivations in active travel behaviour and encourage urban cycling by a wider range of people.Finally, a mathematical framework is derived from first principles to determine speed from cyclist characteristics (power output, gearing, resistance parameters) and roadway attributes. Application of the speed estimation framework to the problem of traffic signal clearance interval timing illustrates the utility for probabilistic, context- sensitive roadway design.

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