How are travel times determined in Chicagoland traffic reports?
July 7th, 2009 | 
Author: WBBM, WGN, and all the other radio stations (even the music stations) use travel times for the major expressways, so how do they determine that?
Two Chicago friends I know have different opinions, one says they hire people to drive and the other says the mix use of cameras and censors.
For about 35 years WGN had helicopters flying around with a city or state police officer giving the reports. WBBM finally called "foul" and the privileged reports stopped. Since then, traffic services, commuters, censors buried in the pavement, expressway cameras, and the internet provide the media the information, they interpret and pass on to their listeners/viewers. They probably use "mapquest" too:
http://www.gcmtravel.com/gcm/maps_chicago.jsp
http://www.traffic.com/Chicago-Traffic/Chicago-Traffic-Reports.html
http://www.mapquest.com/maps?city=Chicago&state=IL&sem=1&ncid=MPQMAP00170000000020&otim=1246026174&spid=29009688#a/maps/l:::Chicago:IL::US:41.883823:-87.632469:city:Cook+County:1/m::7:41.883912:-87.633026:1:::::/io:0:::::f:EN:M:/e
Posted in travel
Huh… Good question.
Their times never seem correct unless you’re in those Express Lanes, so I think they just guess. They probably take their cameras (or censors or both) and try to determine how much of a standstill is going on, and go from there.
Ha! Then again, the times in metro Detroit aren’t always correct , either. have you ever seen our traffic times as reported by The Weather Channel? : ) 696 is usually stuck at 60mph, even in non-peak times… Which we know is at least 15 under what people usually drive.
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For about 35 years WGN had helicopters flying around with a city or state police officer giving the reports. WBBM finally called "foul" and the privileged reports stopped. Since then, traffic services, commuters, censors buried in the pavement, expressway cameras, and the internet provide the media the information, they interpret and pass on to their listeners/viewers. They probably use "mapquest" too:
http://www.gcmtravel.com/gcm/maps_chicago.jsp
http://www.traffic.com/Chicago-Traffic/Chicago-Traffic-Reports.html
http://www.mapquest.com/maps?city=Chicago&state=IL&sem=1&ncid=MPQMAP00170000000020&otim=1246026174&spid=29009688#a/maps/l:::Chicago:IL::US:41.883823:-87.632469:city:Cook+County:1/m::7:41.883912:-87.633026:1:::::/io:0:::::f:EN:M:/e
References :
sensors in the pavement in addition to helicopters.
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