ITS Berkeley

The Ethical Challenges and Professional Responses of Travel Demand Forecasters

Brinkman, Anthony P.
2003

Thirty years ago scholars first presented convincing evidence that local officials use biased travel demand forecasts to justify decisions based on unstated considerations. Since then, a number of researchers have demonstrated convincingly that such forecasts are systematically optimistic-often wildly so-for reasons that cannot be explained solely by the inherent difficulty of predicting the future. Why do modelers-professional engineers and planners who use quantitative techniques to predict future demand for travel and estimate its potential impact on built and proposed transportation...

Compliance, Congestion, and Social Equity: Tackling Critical Evacuation Challenges through the Sharing Economy, Joint Choice Modeling, and Regret Minimization

Wong, Stephen D.
2020

Evacuations are a primary transportation strategy to protect populations from natural and humanmade disasters. Recent evacuations, particularly from hurricanes and wildfires, have exposed three critical evacuation challenges: 1) persistent evacuation non-compliance to mandatory evacuation orders; 2) poor transportation response, leading to heavy congestion, slow evacuation clearance times, and high evacuee risk; and 3) minimal attention in ensuring all populations, especially those most vulnerable, have transportation and shelter. With ongoing climate change and increasing land development...

Understanding and Mitigating Capacity Reduction at Freeway Bottlenecks

Chung, Koohong
2005

Two freeway bottlenecks, each with a distinct geometry, have been investigated in an effort to understand traffic conditions leading to capacity losses (i.e., breakdown). One bottleneck is formed by a horizontal curve and the other by a reduction in travel lanes. These bottlenecks are shown to exhibit breakdowns after queues form immediately upstream. The vehicle accumulations that arise near these bottlenecks are shown to be good proxies for the mechanisms that trigger breakdowns. Evidence is provided to show that these losses can be recovered, postponed or even avoided entirely by...

Life-cycle Environmental Inventory of Passenger Transportation in the United States

Chester, Mikhail V
2008

Energy use and emission factors for passenger transportation modes typically ignore the total environmental inventory which includes vehicle non-operational components (e.g., vehicle manufacturing and maintenance), infrastructure components, and fuel production components from design through end-of-life processes. A life-cycle inventory for each mode is necessary to appropriately address and attribute the transportation sector’s energy and emissions impacts to reduction goals instead of allowing tailpipe emissions to act as indicators of total system performance.

The contributions...

Spatial Models of Morning Commute Consistent with Realistic Traffic Behavior

Lago, Alejandro
2003

Urban planners are increasingly concerned about the sprawling suburban development in metropolitan areas around the world, which they often blame for growing traffic congestion and excessive highway investment needs. This dissertation seeks to shed light on this issue by studying the relationship between morning commute congestion and urban form. The causes and consequences of traffic congestion have been extensively studied in the economics and engineering literatures. Unfortunately, most conclusions have been drawn from very idealized models, which either fail to consider adequately the...

Electric Two-Wheelers in China: Analysis ofEnvironmental, Safety, and Mobility Impacts

Cherry, Christopher R.
2007

Electric powered two-wheel bicycles, while extremely popular in China, have been recently banned by policy makers due to safety, congestion, and environmental concerns. This study investigates the tremendous growth of electric two wheel bicycles in China and compares and quantifies their environmental and safety impacts with the impacts of alternative modes of transportation, such as traditional bicycles, public transportation, or personal cars. The research also analyzes the benefits of electric two wheel bicycles, such as increased mobility and access to opportunities. Additionally, the...

Increasing mobility in cities by controlling overcrowding

Geroliminis, Nikolaos
2007

Various theories have been proposed to describe vehicular traffic movement in cities on an aggregate level. They fall short to create a macroscopic model with variable inputs and outputs that could describe a rush hour dynamically. This dissertation work shows that a macroscopic fundamental diagram (MFD) relating production (the product of average flow and network length) and accumulation (the product of average density and network length) exists for neighborhoods of cities in the order of 5-10km2. It also demonstrates that conditional on accumulation large networks behave predictably and...

Vehicle Reidentification and Travel Time Measurement Using Loop Detector Speed Traps

1998

This dissertation presents a vehicle reidentification algorithm for consecutive detector stations on a freeway, whereby a vehicle measurement made at a downstream detector station is matched with the vehicle’s corresponding measurement at an upstream station. The algorithm should improve freeway surveillance by measuring the actual vehicle travel times; these are simply the differences in the times that each (matched) vehicle arrives to the upstream and downstream stations. Thus, it will be possible to quantify conditions between widely spaced detector stations rather than assuming that...

Deep Discount Group Pass Programs as Instruments for Increasing Transit Revenue and Ridership

Nuworsoo, Cornelius Kofi
2004

Transit properties in the USA have historically experienced loss of market share and low levels of farebox recovery. They resorted to service expansion to maximize subsidies. Experience suggests that: (a) fare increases have not had the desired effect; (b) fare reductions can boost ridership but can also reduce revenue and increase subsidies. The challenge lies with the adoption of such strategies as deep discount group pass programs that can produce more marginal revenue than cost. Deep discount transit pass programs provide groups of people with unlimited-ride transit passes in exchange...

Welfare Analysis of Informal Transit Services in Brazil and the Effects of Regulation

Golub, Aaron David
2003

In Brazil, the recent explosion of informal transport activity is having profound effects on formal, regulated transport systems and is the source of great controversy in the urban passenger transportation arena. A variety of policies are being proposed to manage what has been an uncontrolled growth of the sector. This study seeks to understand the advantages these systems have for users who choose them, and how proposed policies will impact these benefits. A corridor in Rio de Janeiro with substantial informal activity was used as a case study and field trips were made to gather basic...