Traffic Operations and Management

Distributing Synchronous Programs Using Bounded Queues, a coordinated traffic signal application

Zennaro, Marco
Sengupta, Raja
2005

This paper is about the modular compilation and distribution of a sub-class of Simulink programs [10] across networks using bounded FIFO queues. The problem is first addressed mathematically. Then, based on these formal results, a software library for the modular compilation and distribution of Simulink program is given. The performance the library is given. The value of synchronous programming for the next generation of traffic control value is discussed. The adoption of these tools seems to be the natural candidate to address the needs of the traffic engineers. As a case study we present...

A Variable Formulation of Kinematic Waves: Solution Methods

Daganzo, Carlos F.
2003

This paper presents improved solution methods for kinematic wave trafficc problems with concave flow-density relations. As explained in part I of this work, the solution of a kinematic wave problem is a set of continuum least-cost paths in space-time. The least cost to reach a point is the vehicle number. The idea here consists in overlaying a dense but discrete network with appropriate costs in the solution region and then using a shortest-path algorithm to estimate vehicle numbers. With properly designed networks, this procedure is more accurate than existing methods and can be applied...

Toll Pricing “Futures” Market Could Reduce Congestion and Increase Revenue

Fournier, Nicholas, PhD
Patire, Anthony, PhD
Skabardonis, Alexander
2024

Transportation agencies are increasingly relying on tolls to raise revenue and to mitigate congestion, but conventional fixed tolls do not necessarily encourage offpeak use of infrastructure, and high tolls can dampen economic productivity. Dynamically adjusting pricing based on demand can incentivize travelers to avoid peak traffic periods and shift it to other modes, but given the unpredictable nature of traffic, travelers lack the information necessary to accurately predict congestion, so dynamic pricing has minimal effect on demand. Dynamic toll pricing also poses equity concerns for...

Dashboard Cameras Combined with AI Provide an Affordable Method for Identifying Curb Usage

Arcak, Murat
Kurzhanskiy, Alexander
2024

The increasing reliance on transportation network companies (TNCs) and delivery services has transformed the use of curb space. The curb space is also an important interface for bikeways, bus lanes, street vendors, and paratransit stops for passengers with disabilities. These various demands are contributing to a lack of parking, resulting in illegal and double-parking and excessive cruising for spaces and causing traffic disturbance, congestion, and hazardous situations. How cities manage this public asset to support safety and the local economy relies on first understanding the usage...

Wildfire Evacuation Planning Can Be Greatly Enhanced by Considering Fire Progression, Communication Systems, and Other Dynamic Factors

Soga, Kenichi, PhD
Comfort, Louise, PhD
Zhao, Bingyu, PhD
Lorusso, Paola, MSc
Soysal, sena
2021

Wildfires have become a perpetual crisis for communities across California. For life-threatening wildfires, mass evacuation often becomes the only viable option to protect lives. Yet, looking back at recent events, including the devastating 2018 Camp Fire in Northern California, there are significant challenges associated with the evacuation process, such as multi-agency coordination, agency-resident communication, and management of extraordinarily high amounts of traffic within a short period of time. Currently, emergency planners use evacuation models that are typically based on existing...

Policy Brief: Social Equity Impacts of Congestion Management Strategies

Shaheen, Susan, PhD
Stocker, Adam
Meza, Ruth
2019

To better understand the equity implications of a variety of congestion management strategies, researchers at the Transportation Sustainability Research Center (TSRC) at University of California, Berkeley analyzed existing literature on congestion management strategies and findings from 12 expert interviews. The literature review applies the Spatial – Temporal – Economic – Physiological – Social (STEPS) Equity Framework1 to identify impacts and classify whether social equity barriers are reduced, exacerbated, or both by a particular strategy. The congestion management strategies of...

Leveraging the Sharing Economy to Expand Shelter and Transportation Resources in California Evacuations

Wong, Stephen
Shaheen, Susan
2019

In 2017 and 2018, California was severely impacted by a number of devastating wildfires that required thousands of people to evacuate. These evacuations were hampered by poor communication, traffic congestion, and transportation and shelter resource deficiencies. To ensure that all citizens have both transportation and shelter in evacuations, agencies must consider alternative strategies for expanding resources, such as leveraging the sharing economy. To understand the possibility of leveraging the sharing economy to provide housing and transportation in an evacuation, researchers at the...

The Expansion of California’s Freeway Service Patrol Program is Delivering Benefits to Motorists and the Environment

Mauch, Michael
Skabardonis, Alexander
McKeever, Benjamin
2019

The Freeway Service Patrol (FSP) program has the goal of reducing congestion by using fleets of roving tow and service trucks to quickly clear disabled vehicles and address other minor accidents on California’s freeway. The FSP program is jointly managed by Caltrans, the California Highway Patrol (CHP), and regional transportation agencies. Approximately $21.25 million in State transportation funds are provided each year to eligible regional transportation agencies for the FSP program using a formula-based allocation. The Road Repair and Accountability Act of 2017 (SB 1) directs an...

Automated Vehicle Technology Has the Potential to Smooth Traffic Flow and Reduce Greenhouse Gas Emissions

Almatrudi, Sulaiman
Parvate, Kanaad
Rothchild, Daniel
Vijay, Upadhi
Jang, Kathy
Bayen, Alexandre
2022

In an ideal world, all cars along a congested roadway would travel at the same constant average speed; however, this is hardly the case. As soon as one driver brakes, trailing cars must also brake to compensate, leading to “stop and go” traffic waves. This unnecessary braking and accelerating increases fuel consumption (and greenhouse gas emissions) by as much as 67 percent.1 Fortunately, automated vehicles (AVs) — even Level 2 AVs2 which are commercially available today — have the potential to mitigate this problem. By accelerating less than a human would, an AV with flow smoothing...

A Case Study: Testing Wildfire Evacuation Strategies for Communities in Marin County, California

Soga, Kenichi, PhD
Comfort, Louise, PhD
Li, Pengshun, MSc
Zhao, Bingyu, PhD
Lorusso, Paola, MSc
2024

Many small, resource-strapped communities located in areas vulnerable to wildfire don’t have resources to conduct dedicated evacuation studies and many do not consider the impact of background traffic (i.e., normal traffic rather than evacuating traffic) on evacuation. In response, we explored the performance of several generalizable evacuation strategies with background traffic for representative communities in Marin County, including the Ross Valley, Woodacre Bowl, Tamalpais Valley, and an area near Highway 101 and Ignacio Boulevard in Novato (hereafter referred to as ‘Novato...