Many large cities have computerized warning signs to alert drivers to hazards ahead. In 1976, these signs were installed in Pittsburgh when we lived there. I recall one occasion when we were on the parkway and a sign told us, ""Accident ahead - major delay - time 1:17. There was no other reason to believe there had been an accident, but we heeded the warning anyway and got off at the next exit to take another route to our destination. Returning about an hour later in the other lane, we found the sign had told the truth. There was a terrible traffic jam by that time and cars were lined up for miles. The new sign had provided a timely warning and saved us a great deal of time by letting us know what was ahead.
700 years
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