Traffic Operations and Management

Some Properties of a Multi-Lane Extension of the Kinematic Wave Model

Laval, Jorge A.
2003

This paper extends an existing continuum multi-lane formulation for traffic flow, provides a discrete formulation for its numerical solution, and show initial results. The new formulation enables a natural treatment of boundary conditions such as merges, diverges, lane-drops and moving bottlenecks. The proposed model needs few extra parameters and is parsimonious. The look-ahead distance, for example, induces that non-local conditions affect the flow at any time-space point, causing smooth regime changes and fast waves. We find that as the look-ahead distance tends to zero, the solution...

Baseline Evaluation of the Freeway Service Patrol (FSP) I-710 Big-Rig Demonstration Program

Mauch, Michael
Ahn, Soyoung
Chung, Koohung
Skabardonis, Alexander
2005

Freeway service patrol (FSP) is an incident management measure designed to assist disabled vehicles along congested freeway segments and reduce congestion through quick detection, response, and removal of accidents and other incidents on freeways. A two-year demonstration project has been proposed to extend FSP service to big-rigs and other heavy vehicles along the I-710 freeway. The report describes the work performed and the findings from the preliminary evaluation of the proposed I-710 Big-rig FSP demonstration project. The results show that the proposed FSP big-rig project will be cost...

A Simple Traffic Analysis Procedure

Daganzo, Carlos F.
1997

This paper presents a simple approximate procedure for traffic analysis that can be described geometrically without calculus. The procedure, which is graphically intuitive, operates directly on piecewise linear approximations of the N-curves of cumulative vehicle count. Because the N-curves are both readily observable and of direct interest for evaluation purposes (e.g., they yield the total vehicle-hours and vehicle-miles of travel in a time interval, and the vehicular accumulation as a function of time) the predictions made with this method should be practical and easy to test.

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...

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...

An Analysis of Port Selection

Malchow, Matthew Brian
2001

The objective of this research is to study the competition among ports. In particular we study the relation between port characteristics and port market share of maritime traffic. Maritime carriers make two primary decisions that affect ports. In the long-term, they assign vessels to routes. In the short-term, they assign each shipment to a vessel and, with that vessel, a port. In this research, we assume that vessel schedules are fixed and model the assignment of shipments as a function of the attributes that describe each port. For a carrier, some assignments are simpler than other...

Increasing Freeway Merge Capacity Through On-Ramp Metering

Rudjanakanoknad, Jittichai
2005

This research describes field studies of how on-ramp metering can increase the capacity of freeway merges. Some effects of on-ramp metering have been known for a long time. We have known that on-ramp metering can 1) increase freeway flow and speed upstream of a merge; and 2) reduce system-wide delay by alleviating gridlock-causing queues that have blocked off-ramps. However, past studies have not conclusively shown that on-ramp metering can increase the maximum outflow (capacity) of freeway merges. The experiments conducted in the present study verify that on-ramp metering can increase...

Dynamic Stochastic Optimization Models for Air Traffic Flow Management

Mukherjee, Avijit
2004

This dissertation presents dynamic stochastic optimization models for Air Traffic Flow Management (ATFM) that enables decisions to adapt to new information on evolving capacities of National Airspace System (NAS) resources. Uncertainty is represented by a set of capacity scenarios, each depicting a particular time-varying capacity profile of NAS resources. We use the concept of a scenario tree in which multiple scenarios are possible initially. Scenarios are eliminated as possibilities in a succession of branching points, until the specific scenario that will be realized on a particular...

Problem Sets: Fundamentals Of Transportation And Traffic Operations

Daganzo, Carlos F.
1998

These problem sets comprise a supplement to Fundamentals of Transportation and Traffic Operations (C. Daganzo, Pergamon, 1997). Academicians can also obtain a companion set of solutions by writing to "Institute of Transportation Studies, Publications Office, 109 McLaughlin Hall, University of California, Berkeley, CA 94720" or by sending e-mail to its@its.berkeley.edu.

California’s Freeway Service Patrol Program Management: Information System Annual Report Fiscal Year 2004-05

Mauch, Michael
Skabardonis, Alex
2007

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles, and was later expanded to other regions by state legislation in 1991. As of June 2005, there were ten participating FSP Programs operating in California, deploying over 315 tow trucks and covering over 1,500 (center-line) miles of congested California freeways.The...