Predicting speed: The image above shows the average speed of traffic on California roads, based on historical data. The color green indicates wide-open roads, yellow indicates that traffic is slowing, red represents extremely slow traffic, and black (which is not shown on this map) means that traffic is stop and go. The data displayed takes into account the time of day and the day of the week.
Tele Atlas
New trafficking software will enable drivers to find the quickest route to their final destination.
Drivers are always searching for the fastest route--whether they are traveling home on a busy Friday afternoon or rushing to the airport for an early-morning flight. Now Tele Atlas, a Boston-based company that provides digital maps and navigational content, has integrated new trafficking software into its map database so that drivers can find the most optimal route based on speed rather than distance--for any stretch of road at any hour of any day of the week.
"It's like having an experienced cab driver with you all the time who knows which roads to avoid to find the most time-saving route," says Jerry Kim, director of global dynamic content at Tele Atlas.
The software was developed by Inrix, a startup based in Kirkland, WA, that provides real-time and predictive traffic information. The software determines the average speed of roadways across the United States based on two years of historical traffic-speed data collected from commercial fleet vehicles; it uses real-time global positioning software and road sensors from the department of transportation. These billions of data points are then run through proprietary software to create a table of historical traffic patterns based on the hour of the day and the day of the week.
The table contains 168 attributes--24 hours for each of the seven days in a week--and each of the attributes has an average speed that is linked to a road segment, which is identified by a traffic messaging code. The traffic messaging code is embedded into Tele Atlas's maps. When drivers input their starting position and their end position, their navigational device creates a routing algorithm that pulls the traffic messaging codes and then looks up these codes in the data table to identify the average speed of the roadways. This speed is applied to the algorithm, and a color-coded display--in green, yellow, red, or black--of the road segments appears on the device's screen. For instance, the color green indicates a wide-open road, whereas black indicates stop-and-go traffic. Drivers can also view the highways of an entire city to determine which typically move the fastest. (Click here for an animation of traffic flow).
"I can tell you that at 3 P.M. on Friday on a certain stretch of road in Detroit, traffic is typically flowing at 35 miles per hour--and we have done that for almost a million miles of road across the country," says Bryan Mistele, the founder and CEO of Inrix. By integrating this information into its map database, Tele Atlas enables drivers, who want to do things like estimate their time of arrival, to get a much more accurate answer than what is available now.
Agree with the previous reaction. If enough people use the system and follow its advice, escape alternatives themselves clock-up.
The use of historical data to predict where it is going to be busy on the road is only useful for people driving roads not familiar to them. People who drive the same roads everyday know when it gets busy where and will not need the information.
Also, the historical information does not allow for spotting real-time traffic incidents and it is often these incidents that cause the traffic jams in the first place. It seems that the systems under disussion are not set up to spot such incidents.
TomTom, a manufacturer of navigation devices, is testing a system in the Netherlands in co-operation with Vodafone: they claim their system can identify traffic conditions in real time by using tracking the flow of mobile phones. By superimposing this data on the road network, they claim their system can make good guesses on where traffic flows and where traffic does not. They use the location and movement of mobile phones as a proxy to assess road conditions and use this information to give customers route planning advice. How useful this is remains the question, because, as for the systems discussed in the article, escape-route alternatives are scarce and clock-up quicky if too many people make use of re-routed suggestions.
this information is still very useful for routing algorithms, etc. currently most routing algorithms use speed limits for determining the cost of a certain stretch of road.
obviously using data like this in routing algorithms will be more accurate than blindly using speed limit data on a freeway that's congested every afternoon.
Real time flow maps on the dashboard
Try realtime mapping of traffic flows to dasboard of all cars participating. Bottlenecks would show up fast enough and could be compensated by the driver. A real-time version of MS Project would do the trick, too, I think, because other constraints are easily added to determine critical pathways. I think I will try this approach. All I need is your data overlayed with realtime dwonloads and the critical path realtime traffic hypermap is born. this is problem that bother me over the years. Good going.
Charlie
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fiberman
186 Comments
Does it work?
Everybody I know in Germany uses Nav systems all the time. When I tried it, I immediately found a fatal flaw. The Nav system tells you where there are backups and how to go an alternate route. Trouble is, it's telling everybody the same thing. I had the system tell me there was a 3 min backup 1 km ahead but I should take the next exit to avoid it. I did as told and was immediately informed I was not 5 km from another backup which would take 15 minutes to clear caused by rerouting traffic from the first backup.
Garbage in - garbage out!
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jwoodside
6 Comments
Re: Does it work?
They clearly need to monitor in real time also how many people are monitoring their advice and how they are responding to it in order to provide fast correction to that advice. Sounds like it could be confusing... "take the next exit... no don't because everybody is doing that... no they've changed their minds again..."
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Guest (Troubadour )
Re: Does it work?
Feedback loops like that are a tricky problem in real-time flow guidance systems, similar to the "porpoising" experienced in early incarnations of fly-by-wire aircraft. The only way to avoid it would be for the system to anticipate the consequences of its own recommendations on users and adjust for them in advance, creating equilibrium flow.
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