Why We Should Develop a Truly Automated Highway System

1998 ◽  
Vol 1651 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Steven E. Shladover
Keyword(s):  
Energy Consumption ◽  
Travel Time ◽  
Exhaust Emissions ◽  
Driving Behavior ◽  
Highway Capacity ◽  
Automated Highway ◽  
Highway System

The reasons in favor of developing an automated highway system (AHS) are addressed. The anticipated benefits in highway capacity increases, travel time reductions, safety improvements, reduction of driving stress and tedium, elimination of adverse driving behavior, alternative uses of traveling time, more predictable travel time, and reduction of exhaust emissions and energy consumption are reviewed. The concerns that have been raised by those who are skeptical of AHS are then reviewed, indicating which have already been addressed and which remain subject to continuing uncertainty and research.

Axiomatic Approach To Developing Partial Automation Concepts for Deployment of Automated Highway Systems and Partial Invocation of Vision-Based Lane-Keeping and Adaptive Cruise Control

1998 ◽  
Vol 1651 (1) ◽  
pp. 74-79 ◽  
Author(s):  
H.-S. Jacob Tsao
Keyword(s):  
Axiomatic Approach ◽  
Cruise Control ◽  
Highway Capacity ◽  
Automated Highway Systems ◽  
Pros And Cons ◽  
Capacity Gain ◽  
Automated Highway ◽  
Lane Keeping ◽  
Highway System ◽  
Partial Automation

Discussions about the pros and cons of the automated highway system (AHS) visions are nothing but intellectual exercises unless the issue of how to evolve the current highway system toward this end state can be resolved. The primary motivation for the AHS is its potential for considerable highway capacity gain without major acquisition of right-of-way. Many believe that such capacity gain is possible only when lanes are dedicated to the use of those vehicles equipped for full automation. However, to avoid the empty-lane syndrome, there must exist a sufficient population of automation-equipped vehicles that can use the dedicated lane at once or shortly thereafter. Also, if such automation-equipped vehicles can be used only on such dedicated lanes, few people would purchase such vehicles before dedication of lanes on a network basis, the well-known “chicken-and-egg” problem. In this paper partial-automation concepts are proposed that help solve this chicken-and-egg problem. Because of the futuristic nature of the AHS, many technological and nontechnological questions cannot be answered definitely. Assumptions must first be made about the likely or reasonable answers to such questions and then requirements derived for partial-automation concepts based on these assumptions. The goal is for the inferencing process to be rigorous and correct so that only the assumptions are to be debated. The author believes that the assumptions made are reasonable and therefore that the requirements for partial-automation concepts and the actual partial-automation concepts proposed are necessary. Most important, it is hoped that this approach will facilitate a more rigorous process in exchanging ideas and debating AHS deployment issues.

scholarly journals An Asymmetric-Anticipation Car-following Model in the Era of Autonomous-Connected and Human-Driving Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Ammar Jafaripournimchahi ◽  
Wusheng Hu ◽  
Lu Sun
Keyword(s):  
Energy Consumption ◽  
Traffic Flow ◽  
Exhaust Emissions ◽  
Driving Behavior ◽  
Arrival Process ◽  
Motion Information ◽  
Mixed Traffic ◽  
Car Following ◽  
Mixed Traffic Flow ◽  
Car Following Model

Herein, we explored the impact of anticipation and asymmetric driving behavior on vehicle’s position, velocity, acceleration, energy consumption, and exhaust emissions of CO, HC, and NOx in mixed traffic flow. We present an asymmetric-anticipation car-following model (AAFVD) considering the motion information from two direct preceding vehicles (i.e., human-driving (HD) and autonomous and connected (AC) vehicles platoon) via wireless data transmission. The linear stability approach was used to evaluate the properties of the AAFVD model. Our simulations revealed that the drivers’ anticipation factor using the motion information from two direct preceding vehicles in connected vehicles environment can effectively improve traffic flow stability. The vehicle’s departure and arrival process while passing through a signal lane with a traffic light considering the anticipation and asymmetric driving behavior, and the motion information from two direct preceding vehicles was explored. Our numerical results demonstrated that the AAFVD model can decrease the velocity fluctuations, energy consumption, and exhaust emissions of vehicles in mixed traffic flow system.

scholarly journals Economical Speed for Optimizing the Travel Time and Energy Consumption in Train Scheduling using a Fuzzy Multi-Objective Model

2021 ◽  
Author(s):  
Ahmad Reza Jafarian-Moghaddam
Keyword(s):  
Energy Consumption ◽  
Travel Time ◽  
Pollutant Emissions ◽  
Scheduling Problems ◽  
Train Scheduling ◽  
Multi Objective ◽  
Consumption Ratio ◽  
Proposed Model ◽  
Objective Model ◽  
Time And Energy

AbstractSpeed is one of the most influential variables in both energy consumption and train scheduling problems. Increasing speed guarantees punctuality, thereby improving railroad capacity and railway stakeholders’ satisfaction and revenues. However, a rise in speed leads to more energy consumption, costs, and thus, more pollutant emissions. Therefore, determining an economic speed, which requires a trade-off between the user’s expectations and the capabilities of the railway system in providing tractive forces to overcome the running resistance due to rail route and moving conditions, is a critical challenge in railway studies. This paper proposes a new fuzzy multi-objective model, which, by integrating micro and macro levels and determining the economical speed for trains in block sections, can optimize train travel time and energy consumption. Implementing the proposed model in a real case with different scenarios for train scheduling reveals that this model can enhance the total travel time by 19% without changing the energy consumption ratio. The proposed model has little need for input from experts’ opinions to determine the rates and parameters.

Assessment of Arterial Signal Timings Based on Various Operational Policies and Optimization Tools

2021 ◽  
pp. 036119812110111
Author(s):  
Suhaib Al Shayeb ◽  
Nemanja Dobrota ◽  
Aleksandar Stevanovic ◽  
Nikola Mitrovic
Keyword(s):  
Travel Time ◽  
Heavy Traffic ◽  
Future Research ◽  
Signal Timing ◽  
Highway Capacity ◽  
Average Delay ◽  
Highway Capacity Manual ◽  
Simulation And Optimization ◽  
Fort Lauderdale ◽  
Design Engineers

Traffic simulation and optimization tools are classified, according to their practical applicability, into two main categories: theoretical and practical. The performance of the optimized signal timing derived by any tool is influenced by how calculations are executed in the particular tool. Highway Capacity Software (HCS) and Vistro implement the procedures defined in the Highway Capacity Manual, thus they are essentially utilized by traffic operations and design engineers. Considering its capability of timing diagram drafting and travel time collection studies, Tru-Traffic is more commonly used by practitioners. All these programs have different built-in objective function(s) to develop optimized signal plans for intersections. In this study, the performance of the optimal signal timing plans developed by HCS, Tru-Traffic, and Vistro are evaluated and compared by using the microsimulation software Vissim. A real-world urban arterial with 20 intersections and heavy traffic in Fort Lauderdale, Florida served as the testbed. To eliminate any bias in the comparisons, all experiments were performed under identical geometric and traffic conditions, coded in each tool. The evaluation of the optimized plans was conducted based on average delay, number of stops, performance index, travel time, and percentage of arrivals on green. Results indicated that although timings developed in HCS reduced delay, they drastically increased number of stops. Tru-Traffic signal timings, when only offsets are optimized, performed better than timings developed by all of the other tools. Finally, Vistro increased arrivals on green, but it also increased delay. Optimized signal plans were transferred manually from optimization tools to Vissim. Therefore, future research should find methods for automatically transferring optimized plans to Vissim.

Parameter Sensitivity Analysis of a Cooperative Dynamic Bus Lane System With Connected Vehicles

2021 ◽  
pp. 036119812110357
Author(s):  
Meng Xie ◽  
Michael Winsor ◽  
Tao Ma ◽  
Andreas Rau ◽  
Fritz Busch ◽  
...  
Keyword(s):  
Travel Time ◽  
Transition Period ◽  
Penetration Rate ◽  
Simulation Models ◽  
Driving Behavior ◽  
Connected Vehicles ◽  
Microscopic Simulation ◽  
Communication Range ◽  
Bus Lane ◽  
The Impact

This paper aims to evaluate the sensitivity of the proposed cooperative dynamic bus lane system with microscopic traffic simulation models. The system creates a flexible bus priority lane that is only activated on demand at an appropriate time with advanced information and communication technologies, which can maximize the use of road space. A decentralized multi-lane cooperative algorithm is developed and implemented in a microscopic simulation environment to coordinate lane changing, gap acceptance, and car-following driving behavior for the connected vehicles (CVs) on the bus lane and the adjacent lanes. The key parameters for the sensitivity study include the penetration rate and communication range of CVs, considering the transition period and gradual uptake of CVs. Multiple scenarios are developed and compared to analyze the impact of key parameters on the system’s performance, such as total saved travel time of all passengers and travel time variation among buses and private vehicles. The microscopic simulation models showed that the cooperative dynamic bus lane system is significantly sensitive to the variations of the penetration rate and the communication range in a congested traffic state. With a CV system and a communication range of 150 m, buses obtain maximum benefits with minimal impacts on private vehicles in the study simulation. The safety concerns induced by cooperative driving behavior are also discussed in this paper.

Control design of an automated highway system

2000 ◽  
Vol 88 (7) ◽  
pp. 913-925 ◽  
Author(s):  
R. Horowitz ◽  
P. Varaiya
Keyword(s):  
Control Design ◽  
Automated Highway ◽  
Highway System
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