Traffic Theory

Innovative Bus-Lane Deployments in Amman: Proposed Field Experiments

Guler, Ilgin
Cassidy, Michael
2010

Innovative strategies for deploying bus lanes are proposed for field tests in Amman, Jordan. The objective is to reduce delays to buses in the network while minimizing delays to other vehicular traffic. The proposed strategies may be far better options than conventional, static bus lanes, given the test site’s large car demand and low bus frequency. The experiment is designed to be conducted in simple, safe ways, without the need for investment in permanent infrastructure.

Morning Commute with Competing Modes and DistributedDemand: User Equilibrium, System Optimum, and Pricing

Gonzales, Eric J.
Daganzo, Carlos F.
2011

The morning commute problem for a single bottleneck is extended to model mode choice in an urban area with time-dependent demand. This extension recognizes that street space is shared by cars and public transit. It is assumed that transit is operated independently of traffic conditions, and that when it is operated it consumes a fixed amount of space. As a first step, a single fixed-capacity bottleneck that can serve both cars and transit is studied. Commuters choose which mode to use and when to travel in order to minimize the generalized cost of their own trip. The transit agency chooses...

A Dynamic Congestion Pricing Strategy for High-Occupancy Toll Lanes

Jang, Kitae
Chung, Koohong
2010

High Occupancy Toll (HOT) lanes are emerging as a solution to address the underutilization of High Occupancy Vehicle (HOV) lanes and also means of generating revenue for state department of transportation. This paper proposes a method for dynamically determining the HOT toll price in response to the changes in traffic condition and documents procedures for estimating parameters needed for the proposed pricing strategies: revenue maximization and delay minimization. The proposed strategies have been applied to 14-miles of freeway segment in the San Francisco Bay Area, and the findings show...

Intersection Decision Support Project: Taxonomy of Crossing-Path Crashes at Intersections Using GES 2000 Data

Ragland, David R.
Zabyshny, Aleksandr A.
2003

The Intersection Decision Support (IDS) Project is designed to reduce crossing-path (CP) crashes at intersections by providing crucial information to drivers that would help them avoid such crashes. Over the past decade, researchers have used the General Estimates System (GES, a representative sample of police-reported crashes in the US) and other data sources to develop a taxonomy of CP crashes and pre-crash scenarios as groundwork for crash-prevention efforts. The current study builds on and extends prior work by constructing a taxonomy of CP crashes using data from the 2000 GES and...

Safety and Other Impacts of Vehicle Impound Enforcement

Cooper, Douglas
Chira-Chavala, T.
Gillen, David
2002

California vehicle impound law took affect on January 1, 1995. The law allows a police officer to seize a vehicle operated by a person whose license is suspended or revoked or who has never been issued a license. The seized vehicle shall then be impounded for 30 days. In California, a driver must be stopped for some other infraction before his/her license can be checked. The purpose of this evaluation is to assess the impact of Upland's vehicle impound program on traffic safety (crashes and on-the-road behavior) and police department resources and operations.

Cost-Effectiveness of Traffic Safety Interventions in the United States

Vahindnia, Farnaz, PhD
Walsh, Julia PhD
2002

In order to demonstrate the results of all available studies on cost-effectiveness and traffic safety, and report them in a comparable format, we conducted a comprehensive review of the literature on the subject. Knowledge of cost-effective (CE) traffic safety programs that result in reduced motor vehicle crashes and fatalities is essential to city planners, managers, and police. METHOD: Using a systematic approach to literature review, the relevant literature has been identified through the use of electronic databases, hand searching of journals, scanning reference lists, and consultation...

Experimental Evaluation of the Continuous Risk Profile (CRP) Approach to the Current Caltrans Methodology for High Collision Concentration Location Identification

Grembek, Offer
Kim, Kwangho
Kwon, Oh Hoon
Lee, Jinwoo
Liu, Haotian
Park, Min Ju
Washington, Simon
Ragland, David
Madanat, Samer M.
2012

This report evaluates the performance of Continuous Risk Profile (CRP) compared with the Sliding Window Method (SWM) and Peak Searching (PS) methods. These three network screening methods all require the same inputs: traffic collision data and Safety Performance Functions (SPFs), however, depending on how these input parameters are analyzed at the network screening level, the result of the analysis can vary significantly. Findings indicated that the CRP method produced far fewer false positives than SWM and PS. The false negative rates for CRP, SWM and PS were comparable. These findings...

Ridesharing in North America: Past, Present, and Future

Chan, Nelson D.
Shaheen, Susan A.
2011

Since the late-1990s, numerous ridematching programs have integrated the Internet, mobile phones, and social networking into their services. Online ridematching systems are employing a range of new strategies to create “critical mass:” 1) regional and large employer partnerships, 2) financial incentives, 3) social networking to younger populations, and 4) real-time ridematching services that employ “smartphones” and automated ridematching software. Enhanced casual carpooling approaches, which focus on “meeting places,” are also being explored. Today, ridesharing represents approximately 8...

Developing Transportation Response Strategies for Wildfire Evacuations via an Empirically Supported Traffic Simulation of Berkeley, California

Zhao, Bingyu
Wong, Steven D.
2021

Government agencies must make rapid and informed decisions in wildfires to safely evacuate people. However, current evacuation simulation tools for resource-strapped agencies largely fail to compare possible transportation responses or incorporate empirical evidence from past wildfires. Consequently, we employ online survey data from evacuees of the 2017 Northern California Wildfires (n=37), the 2017 Southern California Wildfires (n=175), and the 2018 Carr Wildfire (n=254) to inform a policy-oriented traffic evacuation simulation model. We test our simulation for a hypothetical wildfire...

Reducing Greenhouse Emissions and Fuel Consumption: Sustainable Approaches for Surface Transportation

Shaheen, Susan A.
Lipman, Timothy E.
2007

Climate change is rapidly becoming known as a tangible issue that must be addressed to avoid major environmental consequences in the future. Recent change in public opinion has been caused by the physical signs of climate change–melting glaciers, rising sea levels, more severe storm and drought events, and hotter average global temperatures annually. Transportation is a major contributor of carbon dioxide (CO2) and other greenhouse gas emissions from human activity, accounting for approximately 14 percent of total anthropogenic emissions globally and about 27 percent in the U.S.Fortunately...