Often, getting on an Interstate highway in any major city is not always the best idea. Particularly during a "rush hour", or during road construction, it is as likely that you'll wind up in a parking lot as in your actually getting promptly to your destination.
Television and radio traffic reports can be helpful, but often they are ten or twenty minutes out-of-date. Some cities have begun installing electronic message boards, but again, the information is very general and it can be really old by the time drivers sees it.
Consider this very simple, inexpensive system:
At two mile intervals along an interstate, (weatherproof) inexpensive
SPORTS radar speed guns (often around $100 each) would be installed
above each lane, on either the underside
of a bridge or on a bridging structure that supports highway signage.
Instead of being on continuously, an electronic timer would trigger
each one about once a second. The results, rather than going to a
display readout, would be sent by a radio signal (or actual cable
connection) to arrive as an input line to a standard small (PC) computer.
Even an obsolete computer could be used, so that could be under $200 cost.
That computer would total up 60 (non-zero) readings (one minute's worth of
traffic in that lane) and then divide the number of non-zero readings.
The result would be an average speed for the vehicles that had been
in that lane at that location, virtually in real-time.
The computer would then average the speeds of all the lanes, to get a
representative travel speed for that location during that minute.
Along the shoulder of the highway, two, four, six, eight, and ten miles before that location, a digital display readout would show the (five) speeds for the different locations ahead. If a driver back there is driving on a fairly clear highway, at the posted speed limit, everything might seem well. But, if that driver sees that the average speed drops to 15 mph four miles ahead and to 10 mph six miles ahead, he might consider exiting the highway and taking a frontage road or other alternate path instead.
The proposed readouts would allow drivers to plan ahead. Presently, that sort of planning is not really very possible. If a serious accident eight miles ahead completely blocked the highway, these readouts would let drivers several miles back plan ahead enough to avoid getting stuck. In addition, since a lot of the traffic would then be exiting the expressway miles before the problem area, the Police effort to get traffic past the accident scene would be reduced.
Since this information is nearly in real-time, drivers could already be choosing to exit the expressway even before the Police and ambulances are able to get to an accident. Even if the message boards being installed now had extremely alert operators, they could not provide that quick of guidance for drivers.
Far fewer drivers would be irate from being stuck in bumper-to-bumper traffic. The ones that remained on the highway would be aware of what was ahead and would hopefully be more tolerant from having that additional knowledge.
For a city to install such a system, the cost is extremely reasonable. For each two miles of Interstate, either three or four sports radar speed guns (at about $100 each), a standard (obsolete) PC computer (about $0 to $200), five display readouts (at about $300 each), and some wire or radio transmitters/receivers. That's a total of only a little over $2000 per two-mile stretch of highway. For a fairly large city that has 100 miles of Interstate highway, that means that for $100K, ALL of those highways could be improved with this system.
Millions of drivers would be thankful in the future!
( http://mb-soft.com/public/index.html )
C Johnson, Physicist, Physics Degree from Univ of Chicago