Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 9/27/83; site hplabsb.UUCP Path: utzoo!linus!decvax!ittvax!dcdwest!sdcsvax!sdcrdcf!hplabs!hplabsb!hodor From: hodor@hplabsb.UUCP Newsgroups: net.auto Subject: Eliminate traffic congestion Message-ID: <2349@hplabsb.UUCP> Date: Wed, 27-Jun-84 08:47:07 EDT Article-I.D.: hplabsb.2349 Posted: Wed Jun 27 08:47:07 1984 Date-Received: Sat, 30-Jun-84 06:22:33 EDT Organization: Hewlett Packard Labs, Palo Alto CA Lines: 84 The federal government is implementing a massive road reconstruction plan. Some of this will no doubt be allocated to improving the roads in major cities to try to alleviate some of the traffic congestion. This will cost the people of the United States in taxes. I would like to propose only implementing the repair of the existing roads and approaching the problem of congestion from a different direction. The first part of the proposal is the 55 mph speed limit should be eliminated. This has outlived its time. The control of the maximum speed limit should be set by the states. Below is a table of what happens to the amount of traffic that an already existing road can handle at various speed limits. This is assuming that a safe distance of 1 car length for every 10 miles per hour of separation between cars. I took a car length to be 20 feet. Speed Throughput Density mph Cars/hour cars/mile ---------------------------------- 1 258 240 10 1320 132 55 2234 41 70 2310 33 100 2400 24 Some observations from the above table show that at 1 mph the road becomes a parking lot with a density of 240 cars per mile. If we could regulate the traffic getting onto the freeway the throughput of the freeway would increase. By the above chart the throughput would increase by a factor of nine going to 55 mph. Going from 55 mph to 70 mph only increases the throughput by about 3%. This is due to the reduction in the density of cars that the road could safely take (again the 1 car spacing for each 10 mph). The second part of this proposal involves the use of electronic position detectors for future cars. This device would allow all cars to be about 1 car length apart no matter what the speed. The electronic control would not allow a person to get any closer than a specified distance. The electronic control would control the breaks and put a maximum limit on the speed based on the traffic flow. Electronics are well noted for their ability to react much faster than a human. Below is a table of the speed and throughput of cars using the same road as stated above. Only this time the cars are equipped with this electronic position detector. Speed Throughput mph cars/hour -------------------- 1 132 10 1320 55 7230 70 9240 100 13200 The density of cars could remain a constant of 132 cars per mile. Note that as the speed of the cars increase the throughput of the cars also increase linearly. Also one of the big advantages of this type of device would be the dramatic increase in throughput of the existing freeways. At 55 mph the throughput increases by more than 3 times. If the speed of the cars could be increased to 70 mph the throughput would be increased by more than 4 times. With electronic position detectors in cars the current highway system would be able to support more than 3 times the amount of traffic that we have on our freeways today. I believe this could be done for much less than anything that would try to improve our highway system through more construction. A couple things I like about this idea are: -Not all cars have to have the detector to gain the benefits of the new system. -With the use of high reliability design the additional safety provided by the detector would save lives. -People would spend less time commuting or transporting goods due to the higher speeds that would be possible. This will provide more discretionary time for people and reduce the cost of goods. Conclusion I hope more people write to their state and federal government representatives about eliminating the 55 mph speed limit. Detroit, I hope you pick up on the position detector idea and run with it.