Transportation Engineering Commons^™

A Simulation Framework For Edge Lane Roads And Bicycle Shared Roadways, Nick Sauciur

Master's Theses

Edge Lane Roads, also referred to as Advisory Bike Lanes, are a shared roadway treatment that designates space for cyclists while allowing flexible use of the roadway by motorists. They are commonly applied on lower speed corridors and can be used both where roadway width is limited and where agencies seek to manage vehicle speeds, clarify cyclist positioning, or improve shared roadway operations. The configuration provides visually designated space for cyclists while allowing motorists to encroach into that space when yielding to opposing traffic. Although interest in these facilities is growing in North America, quantitative tools for evaluating their operational …

Investigating The Conversion Of A Signalized Intersection To A Turbo Roundabout, Vyshnavi P. Shetty

Master's Theses

Turbo roundabouts are multilane roundabouts that utilize a spiral design with raised lane dividers to guide traffic flow effectively. While they have seen widespread use in Europe, California is the second state in the US (after Florida) to have installed a turbo roundabout. Turbo roundabouts separate the ingress and circulating lanes. The concept was first proposed and implemented in the Netherlands to address safety concerns and improve traffic flow efficiency on conventional multilane roundabouts.

This research evaluates the first-ever turbo roundabout in California and compares its safety and operational performance with the previously existing 4-legged signalized intersection. The research team …

A 2-D Numerical Model For Evaluating Daylight Penetration In Short Tunnels For Enhanced Driver Safety, Joachim James

Master's Theses

It is commonly assumed that daylight will adequately penetrate short tunnels, leading to the misconception that artificial lighting is unnecessary during the daytime. Past studies revealed higher frequency of crashes in short tunnels and despite that there is lack of national guidelines warranting artificial lighting for short tunnels. Inadequately lit tunnels pose safety risks, while excessive lighting can be costly. Hence, it becomes crucial to investigate the extent of daylight penetration in short tunnels and identify disappearance zones within these tunnels. This research can help determine the necessity of artificial lighting, and which specific areas of the tunnel require lighting. …

An Exploratory Framework For Benchmarking Vehicle Miles Traveled (Vmt) Estimates Associated With University Campuses, Troy Kawahara

Master's Theses

Although vehicle miles traveled (VMT) has become the standard for assessing transportation related impacts in California, some have concerns that many VMT estimates are not properly grounded or informed by real world data, potentially resulting in flawed estimates and impact assessments. This is especially true of special generators, like college and university campuses, which have complex travel patterns distinct from that of the general public. This thesis attempts to resolve a significant disparity observed between two credible VMT estimates for Cal Poly’s campus wide VMT. As part of a campus master planning effort, a VMT estimate was produced in 2019 …

Estimating The Impact Of Infill Housing On Reduction In Vehicle Miles Traveled, Peyton Marie Ratto

Master's Theses

Vehicle miles traveled (VMT) and its relationship with the built environment has been extensively studied. Most notably, five D variables of the built environment including density, diversity, design, destination accessibility, and distance to transit are the key variables included in this research to explain VMT generation from housing developments. This thesis uses prior research that developed robust statistical models and findings to create a framework to estimate VMT reduction affected by infill housing developed using incentives provided by the state compared to a regional comparator. The regional comparator is typically a suburban single-family housing development in the region. The models …

Measuring Accessibility For Pedestrians, Bicyclists, And Transit Riders To Grocery Stores In The Excelsior/Outer Mission Neighborhoods Of San Francisco, Alexandra Lee-Gardner

Master's Theses

Grocery stores are an important amenity in neighborhoods and access to grocery stores is important for health and well-being. While grocery store accessibility is a popular topic of research, studies measuring access for pedestrians, bicyclists, and transit riders are extremely rare. When a new store opened in the Excelsior/Outer Mission districts of San Francisco on a street lacking basic infrastructure for pedestrians, bicyclists, and transit riders, the importance of this study became apparent. The Excelsior/Outer Mission neighborhood has a shocking number of collisions (over 1,100 between 2015 and 2019), elevated levels of walking, biking, and transit ridership, and minimal safe …

Evaluation Of Cost-Effective Alternative Designs For Rural Expressway Intersections, Jonathan Howard

Master's Theses

Despite numerous studies demonstrating the effectiveness of Restricted Crossing U-Turn (RCUT) intersection design, its implementation remains uneven and close to zero in some large states such as California. This research provides a comprehensive framework to estimate the operational and safety performance of future RCUT designs in California. The framework is demonstrated for five intersections located on high-speed rural expressways in California using VISSIM microsimulation models to measure operational performance for each intersection including the base condition with the existing Two-Way Stop-Controlled (TWSC) intersection and two RCUT designs. To evaluate future safety performance, the microsimulation models were further utilized to compile …

Assessing The Impact Of Bicycle Infrastructure And Modal Shift On Traffic Operations And Safety Using Microsimulation, Katherine E. Lee

Master's Theses

A transportation system designed to prioritize the mobility of automobiles cannot accommodate the growing number of road users. The Complete Streets policy plays a crucial part in transforming streets to accommodate multiple modes of transportation, especially active modes like biking and walking. Complete streets are referred to as streets designed for everyone and enable safety and mobility to all users. A strategy of complete streets transformation is to connect isolated complete street segments to form a complete network that improves active mobility and public transit ridership.

This research assessed the impact of efficiently and equitably connecting and expanding the biking …

Analyzing The Safety Effects Of Edge Lane Roads For All Road Users, Marcial F. Lamera

Master's Theses

This thesis acts as one of the first studies that analyzes the safety effects of Edge Lane Roads (ELR) for all road users. This is important since ELRs can be a solution to many issues, such as alleviating congestion, increasing multimodality along roadways, and reducing maintenance costs. ELRs in both North America and Australia were observed. Starting with the North American ELRs, the following study designs were employed to estimate the safety of ELRs: (a) yoked comparison where each ELR installation was matched with at least two comparable 2-lane roads to serve as comparison sites and (b) an Empirical Bayes …

Evaluating Urban Downtown One-Way To Two-Way Street Conversion Using Microscopic Traffic Simulation, Bernice Liu

Master's Theses

Located in the heart of Silicon Valley, Downtown San Jose is attracting new residents, visitors, and businesses. Clearly, the mobility of these residents, visitors, and businesses cannot be accommodated by streets that focus on the single-occupancy automobile mode. To increase the potential for individuals to use non-single-occupancy modes of travel, the downtown area must have a cohesive plan to integrate multimodal use and public life. Complete streets are an integral component of the multi-modal transport system and more livable communities. Complete streets refer to roads designed to accommodate multiple modes, users, and activities including walking, cycling, transit, automobile, and nearby …

Analysis Of The Effects Of Adaptive Ramp Metering On Measures Of Efficiency With A Proposed Framework For Safety Evaluation, Jacky Loh

Master's Theses

Adaptive ramp metering (ARM) is a widely popular intelligent transportation system (ITS) tool that boasts the ability to reduce congestion and streamline traffic flow during peak hour periods while maintaining a lower implementation cost than traditional methods such as freeway widening. This thesis explores the effectiveness of ARM implementation on an 18 mile segment of the Interstate 80 (I-80) corridor in the Bay Area residing in northern California. Smaller segments of this particular segment were analyzed to determine the effective length of ARM on efficiency at various lengths originating from a known bottleneck location. Efficiency values were also compared against …

Sidewalks To Nowhere: A Tool To Prioritize Pedestrian Improvements, Ho Yan Lai

Master's Theses

Walkability as a concept that captures the ability to walk from one place to another has multiple dimensions. Between traversability to being a proxy for better urban places, there are also numerous measurements of walkability that attempts to quantify certain or all aspects of walkability. It is, however, unclear, through a review of available literature, how these measurements of walkability relate to each other statistically. This methodology focuses on generating a framework for analysts to evaluate and prioritize pedestrian infrastructure. WalkScore™ (WS), HCM Pedestrian Level of Service (PLOS), Average Nodal Degree (AND), and Intersection Density are the four metrics selected …

Ridership Ramp-Up For Fixed-Guideway Transit Projects: An Evaluation Of Initial Ridership Variation, Jill Elizabeth Shinn

Master's Theses

Performance-based planning and programming has increased in popularity for transit project funding in recent years. This methodology focuses on quantitative performance measures to inform decision making. For transit projects, projections or observed ridership is the most commonly used performance measure to evaluate project benefits. Conventional wisdom within the transit industry suggests that measuring the performance of a transit project immediately after project opening may not capture all the project’s benefits, since it takes time for a project to realize its short-term ridership potential, a process commonly referred to as ridership ramp-up. While this idea is both intuitive and appealing, especially …

Assessment Of The Potential Of Proposed Stations Of The California High-Speed Rail As Major Hubs For Physical And Economic Development, Seitu Akira Coleman

Master's Theses

This study investigated the potential for development of station catchment areas around the proposed California High-Speed Rail System. The study was prompted by a review of practices of Japanese railway company groups that engage not only in train operations, but also in business diversification and property development within the station areas of their lines. These actions allow the company groups to diversify their revenues streams, increase ridership on their lines, and operate as a whole with net profits. This is in contrast to transit agencies in the United States, which only focus on transporting passengers along their lines and do …

Early Empirical Evidence For The Effects Of Adaptive Ramp Metering On Measures Of Travel Time Reliability, Travis Charles Low

Master's Theses

Adaptive ramp metering (ARM) is a critical component of smart freeway corridors under an active traffic management portfolio. While improving capacity through smart corridors and application of proactive traffic management solutions is less costly and easier to deploy than freeway widening, conversion to smart corridors still represents a sizable investment for a state department of transportation. Early evidence of improvements following these projects can be valuable to agencies. However, in the U.S. there have been limited evaluations, of smart corridors in general and ARM in particular, based on real operational data. This thesis explores travel time reliability measures for the …

Quantifying The Impact Of Truck Only Lanes On Vehicular Emissions On A Limited-Access Highway, Edward Chee Tang

Master's Theses

This thesis seeks to estimate CO₂ emissions on a portion of the U.S. 101 highway in San Luis Obispo County before and after construction of a truck only lane on the Cuesta Grade. Towards that aim, the microsimulation software, VISSIM, was used in conjunction with the Environmental Protection Agency’s emissions model, MOVES. The microsimulation model was calibrated and validated against historical and present traffic volumes obtained from Caltrans with good results using several validation measures. It was found that CO₂ emissions did decrease between 1998 and 2012 (pre and post lane addition), but this effect was shown to …

Estimating Transit Ridership Patterns Through Automated Data Collection Technology: A Case Study In San Luis Obispo, California, Ashley Kim

Master's Theses

Public transportation offers a crucial solution to the travel demand in light of national and global economic, energy, and environmental challenges. If implemented effectively, public transit offers an affordable, convenient, and sustainable transportation mode. Implementation of new technologies for information-harvesting may lead to more effective transit operations. This study examines the potential of automated data collection technologies to analyzing and understand the origin-destination flow patterns, which is essential for transit route planning and stop location placement.

This thesis investigates the collection and analysis of data of passengers onboard San Luis Obispo Transit buses in February and March 2017 using Bluetooth …

Enhancing Capacity And Managing Demand To Increase Short-Term Throughput On The San Francisco-Oakland Bay Bridge, Kevin Reid Carstens

Master's Theses

While there are many proposals for fixing congestion between San Francisco and Oakland in California by adding a new bridge or tube, these solutions will take decades to implement even though a solution is needed now. This thesis assesses sixteen different strategies for reducing congestion in the short-term in the four categories of improving transit, promoting carpooling, implementing intelligent transportation systems practices, and incentivizing alternatives to using the Bay Bridge. Top priorities include HOV improvements on the West Grand Avenue and Powell Street onramps, altering WestCAT Lynx and BART transit services, partnering with rideshare apps to increase transit station accessibility …

Exploring Data Driven Models Of Transit Travel Time And Delay, Bobjot Singh Sidhu

Master's Theses

Transit travel time and operating speed influence service attractiveness, operating cost, system efficiency and sustainability. The Tri-County Metropolitan Transportation District of Oregon (TriMet) provides public transportation service in the tri-county Portland metropolitan area. TriMet was one of the first transit agencies to implement a Bus Dispatch System (BDS) as a part of its overall service control and management system. TriMet has had the foresight to fully archive the BDS automatic vehicle location and automatic passenger count data for all bus trips at the stop level since 1997. More recently, the BDS system was upgraded to provide stop-level data plus 5-second …

Exploring Travel Time Reliability Using Bluetooth Data Collection: A Case Study In San Luis Obispo, California, Krista Purser

Master's Theses

Bluetooth technology applications have improved travel time data collection efforts and allowed for collection of large data sets at a low cost per data unit. Mean travel times between pairs of points are available, but the primary value of this technique is the availability of the entire distribution of travel times throughout multiple days and time periods, allowing for a greater understanding of travel time variations and reliability. The use of these data for transportation planning, engineering and operations continues to expand. Previous applications of similar data sources have included travel demand and simulation model validation, work zone traffic patterns, …

Benefits Of Advanced Traffic Management Solutions: Before And After Crash Analysis For Deployment Of A Variable Advisory Speed Limit System, Alexander Lindsay Chambers

Master's Theses

Variable speed limit (VSL) systems are important active traffic management tools that are being deployed across the U.S. and indeed around the world for relieving congestion and improving safety. Oregon’s first variable advisory speed limit signs were activated along Oregon Highway 217 in the summer of 2014. The variable advisory speed system is responsive to both congestion and weather conditions. This seven-mile corridor stretches around Western Portland and has suffered from high crash rates and peak period congestion in the past. VSL systems are often deployed to address safety, mobility and sustainability related performance. This research seeks to determine whether …

Automated Vehicles: A Guide For Planners And Policymakers, Charlie Coles

Master's Theses

Automated vehicles are those which are capable of sensing their environments in order to perform at least some aspects of the safety-critical control (like steering, throttling, or braking) without direct human input. As a guide for planners and policymakers, the objective of this thesis is to develop a strong foundation for anticipating the potential impacts resulting from advancements in vehicle automation. To establish the foundation, this thesis uses a robust qualitative methodology, coupling a review of literature on the potential advantages and disadvantages of vehicle automation and lessons from past innovations in transportation, with recent trends of the Millennial Generation, …

Exploring Transit Ridership Using Census, Routing & Scheduling, And Stop Characteristic Data, Douglas Harvey Moody

Master's Theses

This study develops, analyzes, and a­­­­­pplies transit-system-specific regression tree models that identify and prioritize transit system improvements through analysis and application of ridership, Census, routing and scheduling, and transit stop characteristic data. Regression trees identify and rank independent variables that split dependent variable datasets into meaningful subsets according to significant relationships with independent variable datasets, and regression tree models can be used to identify and prioritize transit system improvements. In this study, ridership datatypes are the dependent variables (i.e., boardings and alightings) and Census, routing and scheduling, and transit stop characteristic datatypes are the independent variables. Data associated with the …

Investigating The Correlation Between Freeway Service Levels And Freeway Service Patrol Assists, Nora Chin

Master's Theses

The Bay Area Metropolitan Transportation Commission’s (MTC) Freeway Service Patrol’s highway motorist response service is reporting a reduction in their service levels. We analyze the relationship between the reduction in the Bay Area Freeway Service Patrol’s (FSP) motorist assists and changes in vehicle miles traveled (VMT), California Highway Patrol (CHP) reported incidents, and cover research on the impact of new and old vehicle fleet turnover. VMT and CHP incidents have differential effects on FSP assists. Although incidents occurring on freeways with high traffic flows tend to cause more congestion, the trend in local VMT along Bay Area freeway corridors does …

Using Archived Transit Data To Analyze The Effect Of Rainfall On Transit Performance Measures At The Route Level, Nicholas F. Bleich

Master's Theses

This study investigates the effect of rainfall on transit performance measures at the route level in the Puget Sound region of Washington State. Transit agencies are required to report certain performance metrics to the Federal Transit Administration (FTA), but performance measures can also be used to evaluate service and provide customers with information regarding the transit system. Using a three-year sample of archived automatic vehicle location (AVL) and hydrologic data the relationships between ridership, travel time, delay, and rainfall were investigated. The analysis of daily ridership and rainfall resulted in no statistically significant results, however, the results are supported by …

Measuring The Influence That Components Have On Pedestrian Route Choice In Activated Alleys, Samuel Hirsher Gross

Master's Theses

This paper explores how cities have integrated formal planning into improving public space. Through a review of literature on the topic, this the paper identifies the potential design has to renovate narrow streets and alleys, within the public right of way. By preforming an assessment of plans and programs, this paper identifies the common themes or components that have been used by planners, architects, and engineers to improve the urban environment for pedestrians. Based on this information, a pilot study was created to measure the influence the most common components have on pedestrian route choice. The results are then compared …