Traffic Operations and Management

Estimation of Truck Traffic Volume from Single Loop Detectors Using Lane-to-Lane Speed Correlation

Kwon, Jaimyoung
Varaiya, Pravin
Skabardonis, Alexander
2003

An algorithm for real time estimation of truck traffic in multi-lane freeway is proposed. The algorithm uses data from single loop detectors-the most widely installed surveillance technology for urban freeways in the US. The algorithm works for those freeway locations that have a truck-free lane, and exhibit high lane-to-lane speed correlation. These conditions are met by most urban freeway locations. The algorithm produces real time estimates of the truck traffic volumes at the location. It can also be used to produce alternative estimate of the mean effective vehicle length, which can...

Determining the Capacity Benefits of Real-time Signal Control at Intersections

Skabardonis, Alexander
Gallagher, Brian R.
Patel, Kartik P.
2000

Traffic responsive control strategies are increasingly being implemented to improve intersection performance. Critical intersection control (CIC) is using real-time traffic data to better assign green times to conflicting movements. However, the benefits of CIC have not been assessed, and existing methodologies for estimating intersection performance do not account for CIC or other traffic responsive control strategies. The effectiveness of CIC was evaluated at seven signalized intersections in the City of Los Angeles. The findings indicate that CIC generally improves traffic operations....

AHSCAP Dynamic Traffic Assignment Program User’s Manual and Design Description

Hongola, Bruce
1996

This research seeks to provide an understanding of the capacity and throughput require- ments of an automated highway system(AHS) via development of a computer model that represents system capacity and demand, operational characteristics, and defined infras- tructure. To do that, a variety of scenarios representing traffic input to the system must be represented. Also, a variety of infrastructures representing different system configurations must be represented. This includes the locations of entrances and exits.Detailed vehicle-based simulations have been used to investigate AHS capacity...

Operations at Regional Traveler Information Centers: The Case of the TravInfo Field Operational Test - Final Results

Miller, Mark A.
Loukakos, Dimitri
2000

TravInfo is a regional traveler information system in the San Francisco Bay Area. It was a Field Operational Test (FOT) over a two-year period from September 1996 to September 1998 with funding from the Federal Highway Administration and the California Department of Transportation (Caltrans). TravInfo's goal was to broadly disseminate accurate, comprehensive, timely, and reliable information on traffic conditions and multi-modal travel options to the public in the Bay Area. Organizationally, it was structured around a collaborative partnership between and among public and private...

A Methodology for Developing a Traffic Surveillance Investment Program: An Application to Caltrans District 4

Dahlgren, Joy
2000

A method for determining how to develop the most effective traffic surveillance investment program given available resources is developed. The complicated decision structure for deciding where and when to install traffic surveillance and what type of surveillance to install is broken down into a series of steps: identifying information needs, determining which can be met by traffic surveillance, setting criteria for and evaluating the benefits of surveillance in various locations, identifying alternative surveillance methods and estimating their capabilities and costs, comparing the ratios...

Short Term Freeway Traffic Flow Prediction Using Genetically-Optimized Time-Delay-Based Neural Networks

Abdulhai, Baher
Porwal, Himanshu
Recker, Will
1999

Proper prediction of traffic flow parameters is an essential component of any proactive traffic control system and one of the pillars of advanced management of dynamic traffic networks. In this paper, we present a new short term traffic flow prediction system based on an advanced Time Delay Neural Network (TDNN) model, the structure of which is optimized using a Genetic Algorithm (GA). After presentation of the model's development, its performance is validated using both simulated and real traffic flow data obtained from the California Testbed in Orange County, California. The model...

Validation of Daganzo's Behavioral Theory of Mult-Lane Traffic Flow: Interim Report

Banks, James
2002

This report documents results of work completed at San Diego State University during the first year of a research project intended to validate a behavioral traffic-flow theory recently proposed by Daganzo (1,2). Work on this project completed at the University of California at Berkeley will be documented in a separate interim report. In the idealized form developed so far, Daganzo’s theory assumes two types of drivers, aggressive (rabbits) and timid (slugs), and two lane groups, shoulder lanes and passing lanes. In free flow, rabbits travel faster than slugs and the two groups are...

LANE-OPT Users Manual Version 1.0

Lotspeich, David
Hall, Randolph W.
1996

This document is the user manual for LANE-OPT. LANE-OPT is a linear program based software package that optimally assigns traffic to lanes on an automated highway. The program is based on a workload model, such that each lane/segment has a fixed capacity than can be allocated among: (1) straight traffic, (2) lane changes into the lane, (3) lane changes out from the lane, and (4) lane changes that pass through the lane. Each of these four movements produces a user-specified workload. The computer program models the highway as a multi-commodity flow network, where commodities represent...

Are the Objectives and Solutions of Dynamic User-Equilibrium Models Always Consistent?

Lin, Wei-Hua
Lo, Hong
1996

Traffic assignment models are an important component in analyzing the relationship between demand and supply in the transportation network for design, planning, and control purposes. The static traffic assignment model has been used in practice for several decades. With the latest development in the area of Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS), there is an increasing demand for dynamic traffic assignment models to serve as a basis for studying various issues in these areas.Existing dynamic user-equilibrium traffic assignment (DUETA)...

Study of Freeway Traffic Near an Off-Ramp

Cassidy, Michael J.
Anani, Shadi B.
Haigwood, John M.
2000

A bottleneck with a diminished capacity is shown to have arisen on a freeway segment whenever queues from the segment's off-ramped spilled over and occupied its mandatory exit lane. It is also shown that longer exit queues from the over-saturate off-ramp were accompanied by lower discharge rates for non-exiting vehicles. The explanation appears to be rubber-necking on the part of the non-exiting drivers. Whenever the of-ramp queues were prevented from spilling over to the exit lane (by changing the logic of a nearby traffic signal), much higher flows were sustained on the freeway segment...