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

Author(s):  
H.-S. Jacob Tsao

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.

1998 ◽  
Vol 1651 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Mohamed Alkadri ◽  
Hamed Benouar ◽  
H.-S. Jacob Tsao

Automated highway systems (AHS) are a promising concept whose implementation needs to take place in a modular and incremental manner. Immediate implementation of a fully automated highway system may not be feasible or desirable. It does not allow for the necessary testing and evolution of technology, markets, and social change. Recognizing the importance and challenge of progressive, evolutionary AHS deployment, six deployment assumptions are presented, three deployment issues are discussed, and several intermediate automation concepts for evolution toward AHS are proposed. Concepts are presented in the form of “market packages.” Some of these concepts are simple driver aiding systems; others are capable of supporting hands-off and feet-off driving. In the evolutionary path to AHS, a number of comfort and safety enhancements could be realized initially without large infrastructure modifications and without dedicated lanes. Intermediate deployment steps are necessary to help early deployment of partial automation, to allow AHS technology to mature, to establish user confidence, and to create market demand and public acceptance. The packages presented are designed so that they attract the driving public with comfort and safety benefits while requiring no significant roadway infrastructure modification and they encourage motorists to purchase (or retrofit) vehicles with equipment that enables hands-off and feet-off driving, thus building confidence in and creating demand for AHS.


1999 ◽  
Vol 121 (3) ◽  
pp. 462-470 ◽  
Author(s):  
D. Swaroop ◽  
J. K. Hedrick

An important aspect of an Automated Highway System is automatic vehicle following. Automatic Vehicle follower systems must address the problem of string stability, i.e., the problem of spacing error propagation, and in some cases, amplification upstream from one vehicle to another, due to some disturbance at the head of the platoon. An automatic vehicle following controller design that is (asymptotically) stable for one vehicle following another is not necessarily (asymptotically) stable for a string of vehicles. The dynamic coupling between vehicles in such close-formation platoons is a function of the available information (communicated as well as sensed), decentralized feedback control laws and the vehicle spacing policy in use. In the first half of this paper, we develop a framework for establishing conditions for stability of the string in the presence of such dynamic interactions. We then develop a metric for analyzing the performance of a platoon resulting from different vehicle following control algorithms. This metric is the guaranteed rate of attenuation/non-amplification of spacing errors from one vehicle to another. In the latter half of this paper, we outline and analyze various constant spacing vehicle follower algorithms. All these algorithms are analyzed for sensing/actuation lags.


1982 ◽  
Vol 9 (3) ◽  
pp. 385-398 ◽  
Author(s):  
John F. Morrall ◽  
Al Werner

Rural highway capacity, level of service, and other planning criteria are based on outdated information from the United States where the operating environment and traffic conditions are often quite different from those in Canada. Much of the information on rural two-lane highway overtaking and capacity in the 1965 Highway Capacity Manual (HCM) can be traced to data collected as long ago as 1938. Rural two-lane highway capacity and overtaking concepts in use today have remained essentially unchanged since they first appeared in the 1950 Highway Capacity Manual.This paper presents the findings of an investigation into speed–volume relations, platooning, and overtaking on the primary two-lane rural highway system in Alberta, British Columbia, and the National Parks.The principal findings are: (i) there is little relation between speed and volume over the range of volume observed — up to 1700 vehicles per hour, (ii) the average speed at 1000 vph was found to be 20–25 km/h higher than that predicted in the HCM, (iii) the backward bending portion of the speed–volume curve was not observed, (iv) speed distributions at flow rates of 1200 vph showed a marked increase in speed over that in the HCM, and (v) speed distributions of free-moving vehicles indicate a higher proportion of vehicles travelling at uniform speed.The implication of the findings is that the level of service on two-lane rural highways is much higher than that given in the HCM. This, however, is not the case on most of the primary two-lane highway system in western Canada. Despite low volumes, in the 2500–5000 average daily traffic range, drivers perceive a low level of service. This is attributed to a high proportion of long distance (over 300 km), high-speed trips, in rolling terrain with restricted sight distances, through sparsely developed territory with few intermediate stops. Thus motorists spend most of their journey travelling in high-speed platoons resulting in a high driver workload and a propensity to take risks when overtaking.The paper concludes with a recommendation that a nation-wide effort be mounted to collect speed–volume, headway, platooning, and passing data over the full range of highway operating conditions on a year-round basis. A second recommendation is that provincial highway departments in Canada investigate the concept of platooning and opportunity to overtake for evaluating their two-lane highways. More attention should be given to the education and testing of drivers in the skills of overtaking on rural highways. Also proposed is an evaluation of currently accepted, safe passing sight distances, which may be inadequate for the current operating conditions and traffic mix. Alternatives to four lanes, such as alternating passing lanes with early warning signs (to inform the driver of overtaking opportunities a specified distance ahead in order to reduce driver frustration and prevent dangerous passes), need evaluation as well. The paper concludes with a comment on the possible impact of lower speed limits and vehicle control devices, such as the cruise control, on platooning, overtaking, and level-of-service measurement.


Author(s):  
Steven E. Shladover

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.


1997 ◽  
pp. 29-48 ◽  
Author(s):  
Youngbin Yim ◽  
Mark A. Miller ◽  
Paul Hellman ◽  
Mohammad Sharafsaleh

Sign in / Sign up

Export Citation Format

Share Document