As the links below demonstrate (thanks!), places in the US and UK track traffic speed and post it as maps. (I mean the actual speed of traffic, not the speed limit.)
It would be nice if this information, averaged over time, would become part of printed maps.
Once enough vehicles have electronic gadgetry that is aware of the car's motion, this will be easy to extend to non-highways; the GPS map display in a car would get colorized with real-time speed information received from other cars in the vicinity.-- jutta, Oct 03 1999 Vauxhall Trafficmaster http://buypower.vau...l.co.uk/trafficnet/Dynamic speed maps of UK motorways [clive, Oct 03 1999] Caltrans speed maps http://www.cagenter...es.com/Traffic.htmlDynamic speed maps of California [clive, Oct 03 1999] WSDOT speed maps http://www.wsdot.wa.../PugetSoundTraffic/Dynamic speed maps of Seattle and Tacoma, WA [egnor, Oct 03 1999] Chicagoland Expressway Congestion Map http://www.travelin...CM/chicagoland.htmlDynamic speed maps of the Chicago expressway system. [koz, Oct 03 1999] Tracking highway speed by cell phones http://www.sjmercur...ess/top/traffic.htmAnother possible way to track traffic congestion without devices embedded in the highway or in the cars. Simply track the speed of the cell phone radio signals as people whiz by... [koz, Oct 03 1999] turn maps http://www.halfbake...om/idea/turn_20maps [egnor, Oct 03 1999] traffic agents http://www.halfbake...ea/traffic_20agents [egnor, Oct 03 1999] San Diego speed map http://www.dot.ca.g.../sdmap/mapmain.htmlSan Diego speed map [gd, Oct 03 1999] Atlanta Georgia speed map http://www.georgia-...ator.com/tview.htmlOnly covers major highways, but is handy. [krelnik, Oct 02 2002] Yahoo speed maps. http://maps.yahoo.com/traffic [jutta, Jan 16 2005] If you can collect and distribute this in realtime, it can be used for route tweaking. That is, when my car recognizes that I'm headed for home (or my favorite lunch place), it can look at the route I usually take on the speed map to see if there's a problem, and suggest a tweak.-- sdpinpdx, Oct 12 1999 Wouldn't it be useful to know the legal speed limit of a road also, and if it is a speed trap?-- NoDInIt, Dec 15 1999 A variation of this would be to occasionally paint stripes on the road at a pitch such that, if you were going exactly the speed limit, 60 of the stripes would go by in one second.
Then, cars could be equipped with detectors which look for these stripes and using your present speed, calculate the speed limit and highlight it on your spedometer.
It strikes me that such stripes would make an audible sound (if painted on in that thick road marking style). You could paint stripes on the road which played and audible message ("School Zone: Excercise Caution").-- jimfl, Jan 06 2000 The latter.-- jutta, Jan 23 2001 "Driving into a city, one can generally assume a certain amount of slow down due to congestion..."
If you think that's an adequate description, you've clearly never lived in an area with heavy congestion. In this area, the amount of time it takes to get from Point A to Point B can vary by as much as an order of magnitude depending on the route you choose, the precise time of day, and the specific day of the week.
Locals in the Seattle area, for example, know that attempting to travel westbound on SR 520 between I-405 and 92nd Ave at 4:30 PM on Friday is an exercise in painful futility, or that there are frequently inexplicable slowdowns on I-5 north of the ship canal bridge. Someone visiting from out of town wouldn't know these things, and certainly wouldn't know which alternative routes to take.
(Having been in the "out of towner" role in cities like New York and San Francisco, I can attest that it's not obvious. "Oh my god, you tried to go crosstown in Manhattan on a Sunday morning? You should have taken ...")
The radio might help, but you're not guaranteed to hear a sufficiently details traffic report in time to help your planning, and even if you do you'll have to correlate terms like "the S-curves" to features on that Rand McNally map of yours.
The real issue is in representing intensely time-varying data on a static paper map.-- egnor, Jan 24 2001 waugsqueke: what you describe is fine for a low-traffic region. Living in the San Francisco bay area, I have seen 50-mile stretches of highway, zoned for "maximum speed 65," stuck in a crawl of 15mph or less because of congestion. Clearly I would want to know when that is the case so I could potentially reroute my trip. The DOT California web site (www.dot.ca.gov) has links for San Diego, Los Angeles, and San Francisco speed maps, but I could only get something back from the San Diego link.
But I also want to be able to get this data in my car once I leave. Then when I approach a slowdown, I can see if it's just a bad case of rubbernecking that will be over in a few miles, or if it's an epidemic slowdown that needs to be avoided.
Of course, with the readiness of such information in one's car, the "fast" roads would be quickly discovered.-- gd, Mar 23 2001 I imagine you'd want many different pages for each region, then, so you could represent different times of day, days of the week, seasons, and maybe special events.-- moonmoose, Mar 24 2001 Congrats on your prescience.-- bristolz, Jan 16 2005 random, halfbakery