Traffic Operations and Management

New Approach to Bottleneck Capacity Analysis: Final Report

Banks, James H.
2006

A capacity analysis approach intended as an alternative to the traditional Highway Capacity Manual (HCM) method was evaluated. One- and two-stage models of pre-queue and queue discharge flow (each of which might be thought of as representing “capacity” in some sense) were developed and compared with one another and the HCM method. Two-stage models related capacity flows to intervening variables, including average time gaps (average time separations between the rear of a vehicle and the front of one following it) in the critical lane (that with the highest flow rate) and the critical lane...

Evaluation of the ACC Vehicles in Mixed Traffic: Lane Change Effects and Sensitivity Analysis

Ioannou, Petros
Stefanovic, Margareta
2003

Almost every automobile company is producing vehicles with Adaptive Cruise Control (ACC) systems that allow a vehicle to do automatic vehicle following in the same lane. The ACC system is designed for driver comfort and safety and to operate with manually driven vehicles. These characteristics of ACC were found to have beneficial effects on the environment and traffic flow characteristics [1, 2, 3] by acting as filters of a wide class of traffic disturbances. It has been argue that the smooth response of ACC vehicles to high acceleration disturbances or large position errors creates large...

Highway Traffic Data Sensitivity Analysis

Lu, Xiao-Yun
Coifman, Benjamin
2007

This report is divided into two parts:•Part I - Highway Traffic Data Sensitivity Analysis in Systems Approach. This work has been conducted by Dr. Xiao-Yun Lu at California PATH, U. C. Berkeley.•Part II - Empirical and Analytical Results for Sensitivity to Loop Station Spacing. This work has been conducted by Benjamin Coifman in Civil Engineering, Ohio State University.Since the aspects of the problem considered and approaches adopted by the two are different, it is thus necessary to separate the report into two parts. Each part is self-content.

An Assessment of Opportunities for Bus Rapid Transit in the San Francisco Bay Area

Miller, Mark A.
2005

This report presents the findings from an investigation of opportunities to implement bus rapid transit systems in the San Francisco Bay Area with a focus on bus transit routes that travel on the state’s highway system. A primary component of this project has been the consideration of inter-connectivity and regional aspects of bus rapid transit systems deployment in the Bay Area. We examined approximately 200 bus transit routes in the Bay Area that lie on the state highway system from which five routes were identified as likely candidates for bus rapid transit implementation. Two of the...

High Occupancy Vehicle (HOV) System Analysis Tools: Statewide HOV Facility Performance Analysis

Jang, Kitae
Chan, Ching-Yao
Du, Yao-Qiong
Chu, Lianyu
Yang, Ming-Hsun
Recker, Will
2012

The two most common types of high occupancy vehicle (HOV) lanes in California are continuous access, prevalent in Northern California, and buffer-separated limited access, prevalent in Southern California. This report describes the evaluation of operational performance of HOV facilities in several regions in California with different access types as well as a before-after comparative study of California facilities where access types were converted in recent years. A set of performance measures were defined and selected to indicate how well the HOV facilities achieve intended goals –...

Improving the Traffic Census and Highway Performance Monitoring System (HPMS) Programs

Mauch, Michael, PhD
Skabardonis, Alex, PhD
2020

The objective of this research study was to support the Traffic Census and Highway Performance Monitoring System (HPMS) Programs in identifying locations for motorized traffic data collection on public roads in California. The study analyzed the traffic census count locations for each District to determine at which Census count locations the automated and continuously collected Caltrans Performance Measurement System (PeMS) data could be used in lieu of manual traffic counts. Next, this research identified and evaluated count locations for motorized traffic data collection on non-State...

Event-based ATIS: Practical Implementation and Evaluation of Optimized Strategies

Jayakrishnan, R.
Tsai, Wei K.
Oh, Jun-Seok
Adler, Jeffrey
2001

This project further adapt and enhance the previous research of relevance to event-based Advanced Traveler Information Systems (ATIS) and implement the algorithms for traffic management in Anaheim. This study is also answering some basic questions in ATIS implementation associated with routing strategies, driver’s compliance and network performance. This research develops algorithms for static and dynamic optimal Changeable Message Signs (CMS). The optimized CMS schemes are based on performance evaluations using a traffic simulation-based evaluation model, DYNASMART (Dynamic Network...

Relationships Among Urban Freeway Accidents, Traffic Flow, Weather, and Lighting Conditions

Golob, Thomas F.
Recker, Wilfred W.
2003

Linear and nonlinear multivariate statistical analyses are applied to determine how the types of accidents that occur on heavily used freeways in Southern California are related both to the flow of traffic and to weather and ambient lighting conditions. Traffic flow is measured in terms of time series of 30-second observations from inductive loop detectors in the vicinity of the accident prior to the time of its occurrence. Results indicate that the type of collision is strongly related to median traffic speed and to temporal variations in speed in the left and interior lanes. Hit-object...

Analysis of Bogota's Bus Rapid Transit System and its Impact on Land Development

Taiga, F
Rodriguez, DA
2004

Recent experiences in Latin American cities supporting world-class public transportation systems have resulted in the creation of livable spaces with a significant potential to spur land development. In cities like Bogota, Colombia, and Curitiba. Brazil, bus rapid transit (BRT) has re-emerged as a cost-effective transportation alternative for satisfying growing demands for urban mobility. Bogota's BRT system has allowed for a 32 percent reduction in average travel times and significant reduction in accident and air pollution levels along the busway corridors. Although previous...

Bicycle Detection and Operational Concept at Signalized Intersections

Shladover, Steven E.
Kim, ZuWhan
Cao, Meng
Sharafsaleh, Ashkan
Li, Jingquan
Leung, Kai
2009

In support of efforts to improve traffic signal timing to accommodate the needs of bicyclists, observations have been made of the timing of bicyclists’ intersection crossing maneuvers. Video recordings were made of bicyclists’ crossings and the video images were processed to extract the bicyclists’ trajectories. These were synchronized with video images of the traffic signals so that the timing of the bicyclists’ maneuvers could be determined relative to the signal phase. The processed data have yielded cumulative distributions of the crossing speeds of bicyclists who did not have to stop...