11-04-2012, 02:54 PM
automated highway systems
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ACKNOWLEDGEMENT
This seminar would not have been possible without the guidance and the help of several individuals who in one way or another contributed and extended their valuable assistance in the preparation and completion of this study.
First and foremost, my utmost gratitude to my supervisor of their work, F.A.Mir, (Associate Professor) for his guidance and useful suggestion , which helped me in completing the seminar in time.
I would also like to express my heartfelt thanks to my batch mates for their help and wishes for the successful completion of this seminar.
Last but not the least, my family and the one above all of us, the omnipresent God, for giving me the strength to complete this seminar.
ABSTRACT
Automation can reduce accidents and congestion on highways by using computers to drive vehicles. Some issues need to be resolved before Automated Highway Systems (AHS) can be used. Ideally, AHS would only be used on dedicated lanes, but mixed automated/manual traffic is seen as a possible stepping stone. Engineers must also decide on the roles of onboard and infrastructure intelligence. AHS must also overcome the social barrier of legal liability. Incremental deployment can be used to solve these problems by introducing vehicle intelligence in small steps.
1. INTRODUCTION AND BACKGROUND
A major long-term element of Intelligent Transportation Systems research and development is Automated highway Systems (AHS). The AHS program is a broad international effort “to provide the basis for, and transition to, the next major performance upgrade of the vehicle / highway system through the use of automated vehicle control technology
1.1What is AHS?
An Automated Highway System is a vehicle and road based system that can drive a vehicle automatically. This is done using sensors that serve as the vehicle’s eyes, determining lane position and the speed and location of other vehicles. Actuators on the throttle, brake, and steering wheel give the vehicle the commands that a driver normally would. AHS vehicles often also have equipment to communicate with other AHS vehicles. The concept of an Automated Highway has been around for a long time. General Motors displayed a working model of an automated highway at the 1939 World’s Fair in New York City. Automated trains have been in use since the 1960’s. But it has not been until recently that the technology has become available to build Automated highways and vehicles. The term “fully automated intelligent vehicle-highway system” is interpreted to mean a system that:
Evolves from today’s roads (beginning in selected corridors);
Provides fully automated “hands-off” operation at better levels of performance than today’s roadways in terms of safety, efficiency, and operator comfort
and
Allows equipped vehicles to operate in both urban and rural areas on highways that are both instrumented, and not instrumented.
1.2 Why Automated Highways?
1.2.1 Safety
Ninety percent of all vehicle accidents result from driver-related factors –inattentiveness, inability to respond quickly enough, or bad driving decisions.Over 40,000 people die annually in motor vehicle accidents and property damage is estimated at over $150 billion. Electronic systems that never take over some or all of the driver’s responsibilities are the most promising method of reducing these accidents. Analyses of causes show that highway accidents could be reduced between 31 and 85 percent with the use of electronic collision avoidance technologies and fatal crashes could be reduced by at least 50 percent .
1.2.2 Efficiency
The National highway system carries eighty-nine percent of passenger ground - miles traveled and thirty-two percent of the ton-miles of commercial freight travel. The number of vehicles on the roads has doubled in the last ten years while highway capacity has for the most part, remained the same. Consequently, the average speed on urban highways and crowded corridors during rush hour is 36 miles per hour. This loss of time and productivity costs the US $50 billion annually .One solution that engineers are exploring now is an Automated Highway System (AHS). By reducing or eliminating driver error and placing cars more closely together safely on the highways, Highways throughout could be doubled or tripled.
1.2.3 Air Quality
AHS has the potential to reduce traffic delays and traffic jams. As a result, fewer vehicles will be stopped in traffic where they continue to pollute while they aren’t going anywhere. Smoothing out the flow of traffic would also reduce fuel consumption. AHS could eliminate the “slinky effect” of stop and go highway driving which accounts for most vehicular emissions and fuel use.
1.3History of AHS
1.3.1 AHS from 1991-94
In 1991, American Road Congress passed the Intermodal Surface Transportation Efficiency Act (ISTEA) which introduced funding for many Intelligent Transportation Systems (ITS). Part B, Section 6054 (b) of that Act reads:
The Secretary shall develop an automated highway and vehicle prototype from which future fully automated intelligent vehicle-highway systems can be developed. Such development shall include research in human factors to ensure the success of the man-machine relationship. The goal of this program is to have the first fully automated roadway or an automated test track in operation by 1997. This system shall accommodate installation of equipment in new and existing motor vehicles.
AHS was at that time called Intelligent Vehicle - Highway Systems (IVHS). Falling under the general category of ITS, the stated goals of the system were:
1. Enhancement of surface transportation efficiency
2. Achievement of national transportation safety goals
3. Protection and enhancement of the natural environment and communities affected by surface transportation
4. Accommodation of the needs of all users of surface transportation systems
5. Improvement of the Nation’s ability to respond to emergencies and natural disasters
Because these goals were so broad, the US Department of Transportation (USDOT) formed the Joint Program Office (JPO) which brought together the Federal Highway Administration, Federal Transit Administration, and National Highway Traffic Safety Administration and several other DOT administrations. From 1992-1994, only research and analysis on IVHS was done. Engineers mainly worked on human factors research and traffic safety analysis.
1.3.2 From 1994-97
In 1994, the work in IVHS was contracted out to the National Automated Highway Systems Consortium (NAHSC), a partnership of government, industry, and universities. 80 percent of funding came from the USDOT and the remaining 20 percent from the NAHSC partners. It was their job to design and demonstrate a working Automated Highway System by the end of 1997. They began by establishing design and performance objectives and defined several Representative System Configurations (RSCs). They then chose the best RSC and built prototype vehicles and a test roadway.
In August of 1997, the NAHSC performed its “Proof-of-Technical-Feasibility Demonstration”. Its purpose was to show Congress and the world that automated highways are possible and that they do provide the expected safety and efficiency benefits. Eight Buick Le Sabres were equipped with throttle, brake, and steering actuators, magnetometers in the front and rear bumpers, a forward-looking radar, communications equipment, and two Pentium computers. Ceramic magnets 1.2 meters apart were imbedded into the roadway so that the vehicles could keep their lanes. A 7.6- mile stretch of Interstate 15 north of downtown San Diego, California for the test track. The high-occupancy vehicle lanes were used because they were separated from manual traffic. The eight vehicles drove a total of about 8,000 miles without any safety incidents.The NAHSC was decommissioned after it had achieved its goals of designing and building the first AHS.