Connected and Automated Vehicles

Evaluation Of Work Crew And Highway Hazard Conspicuity

Misener, Jim
1998

The report quantitatively addresses conspicuity of highway features, particularly in work zones, from the perspective of driver detection and driver decision making. The study focuses on evaluating the detection process, selecting and exercising human perception-acquisition models suitable for quick running and larger scale microsimulations to evaluate system effectiveness of pre-Automated Highway System (AHS) driver-assist systems. The report describes this process and provides a detection example of a driver-assist collision avoidance model.

A Network Layer for Intelligent Vehicle Highway Systems

Eskafi, Farokh
Zandonadi, Marco
1999

The objective of this paper is to design the network layer of a communication stack to be used in Automated Highway Systems (AHS). The communication model we propose allows cars to form private subnets, the configuration of which can change dynamically. Each car be part of multiple subnets and can send broadcast, multicast and point-to-point messages to other vehicles (both on the same subnet and on others, through a routing mechanism). Each subnet is managed by a server: a car that is in charge of accepting/rejecting join requests and of keeping a consistent state within the subnet....

Robust Automatic Steering Control for Look-Down Reference Systems with Front and Rear Sensors

Guldner, Jurgen
Sienel, Wolfgang
Tan, Han-Shue
Ackerman, Jurgen
Patwardhan, Satyajit
Bunte, Tilman
1997

This paper describes a robust control design for automatic steering of passenger cars. Previous studies [l-3] showed that' reliable automatic driving at highway speed may not be achieved under practical conditions with look-down reference systems which use only one sensor at the front bumper to measure the lateral displacement of the vehicle from the lane reference. An additional lateral displacement. sensor is added here at the tail bumper to solve the automatic steering control problem. The control design is performed stepwise: First, an initial controller is determined using the...

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

Harb, Mustapha, PhD
Malik, Jai, PhD
Circella, Giovanni, PhD
Walker, Joan L., PhD
2022

Forty-three households in the Sacramento region representing diverse demographics, modal preferences, mobility barriers, and weekly vehicle miles traveled (VMT) were provided personal chauffeurs for one or two weeks to simulate travel behavior with a personally-owned, fully autonomous vehicle (AV). During the chauffeur week(s), the total number of trips increased on average by 25 percent, 85 percent of which were “zero-occupancy” (ZOV) trips (when the chauffeur is the only occupant). Average VMT for all households increased by 60 percent, over half of which came from ZOV trips. VMT...

Synthesis of State-Level Planning and Strategic Actions on Automated Vehicles: Lessons and Policy Guidance for California

Wong, Stephen
Shaheen, Susan, PhD
2020

This synthesis provides a summary and comparative analysis of actions states across the United States are taking inresponse to automated vehicles (AVs). The research focuses on state-level stakeholder forums (e.g., task forces, committees) and state-level strategic actions (e.g., studies, initiatives, programs) initiated by a state legislature, agovernor, or a state agency. The analysis found that AV stakeholder forums and strategic actions address a diverse set offocus areas, but they pay minimal attention to the implications of AVs on the environment, public health, social equity, land...

“Don’t Keep Us Out of the Revolution!”: Accessibility and Autonomous Rideshare in California

Heuser, Katie L.
2024

Robotaxi services, or rideshare operated by autonomous vehicles, present an opportunity for independent and convenient transportation for people with disabilities. The proliferation of robotaxis in California has been met with mixed reactions from the disability community. To better understand perceptions of and expectations for robotaxis, this report uses semi-structured interviews with representatives from disability advocacy organizations. For many people with disabilities, especially for people with intellectual, developmental, and/or physical disabilities, robotaxis are inaccessible....

Real-World Simulations of Life with an Autonomous Vehicle Suggest Increased Mobility and Vehicle Travel

Harb, Mustapha
Walker, Joan
Malik, Jai
Circella, Giovanni
2021

Fully autonomous vehicles are expected to have a profound effect on travel behavior. The technology will provide convenience and better mobility for many, allowing owners to perform other tasks while traveling, summon their vehicles from a distance, and send vehicles off to complete tasks without them. These travel behaviors could lead to increases in vehicle miles traveled that will have major implications for traffic congestion and pollution. To estimate the extent to which travel behavior will change, researchers and planners have typically relied on adjustments to existing travel...

Insights on Autonomous Vehicle Policy from Early Adopter Cities and Regions

Chatman, Daniel G., PhD
Moran, Marcel E.
2019

Autonomous vehicles (AVs) are being widely tested and piloted to carry passengers and freight. However, the potential uses and impacts of AVs in communities are uncertain. There are claims that AVs may be able to improve road safety, make travel more convenient, lower shipping costs, and reduce the need for automobile parking. But there are also concerns that AVs may increase road congestion, reduce transit ridership, compete for curb space, and even increase urban sprawl. To better understanding how cities and regions are currently engaging with and planning for AVs, twenty interviews...

The Benefits and Challenges of Incorporating Uber and Lyft in Subsidized Ride Programs that Serve Vulnerable Populations

Halpern, Jeremy
Deakin, Elizabeth
Parker, Madeleine
2020

Cities, transit agencies, and social service providers across the U.S. have implemented programs that provide taxi subsidies for people who have difficulty driving a car or using the regular transit system. These programs usually serve older residents and people with disabilities, though a few also serve low income users. Taxi subsidy programs provide curb-to-curb or door-to-door transportation at a fraction of the cost of paratransit.1 However, as Transportation Network Companies (TNCs), such as Uber and Lyft, have entered markets around the country, taxi availability has declined,...

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...