Cellphones to Monitor Highway Traffic

Roland Piquepaille writes "On February 8, 2008, about 100 UC Berkeley students will participate in the Mobile Century experiment, using GPS mobile phones as traffic sensors. During the whole day, these students carrying the GPS-equipped Nokia N95 will drive along a 10-mile stretch of I-880 between Hayward and Fremont, California. 'The phones will store the vehicles' speed and position information every 3 seconds. These measurements will be sent wirelessly to a server for real-time processing.' As more and more cellphones are GPS-equipped, the traffic engineering community, which currently monitors traffic using mostly fixed sensors such as cameras and loop detectors, is tempted to use our phones to get real-time information about traffic."

Re:WARNING: PARENT IS TROLL

[Datamonstar]

Disable javascript for all but trusted sites.

Re:Measuring changes results

[palegray.net]

I wonder if these sort of systems might lead to real-time changes in toll prices some day. Transportation authorities could leverage real-time stats to charge more for passage during peak traffic periods, and this sort of system would accommodate unexpected increases without any additional effort on their part. It could even sense traffic congestion issues in other areas and anticipate upcoming loads. Not that I agree with such practices, just wondering if they'll be implemented. Couple this with highly expanded automatic tolling systems in the future and you've got a recipe for profit (at least for the state).

I live in tUSA

[stomv]

and ditched my car 7 years ago. I live in Boston across the street from a subway stop. There's another one a few hundred yards away, a third line 1 mile away and a fourth 1.3 miles away. I ride my bicycle year round for many trips 5 miles or less, and arrive faster than the subway or a car. Walking a mile is also no big deal, and I occasionally car pool if a neighbor and I are both headed to a meeting or event.

What about groceries? Smaller trips or deliveries [peapod.com]. What about big purchases? If I ever needed one, I'd borrow a friend's car or sign on to zipcar [zipcar.com]. What about weekends in NYC? I take Acela [amtrak.com] or the bus. What about weekends in rural Vermont? I rent a car for $40 a day. The combined total of non-air travel for my wife and I: $2500/yr, and that includes a combined total of 5 months of time out of Boston. Can your car ownership costs -- insurance, gas, tires, lubes, car payment/depreciation, parking, tickets, tolls, taxes, and repairs match that?

Yeah, you can ditch your car. Doesn't mean you'll never have to borrow or rent one, but it does mean you'll likely save money, operate an auto for fewer miles per year, get a bit more exercise, have a chance to read a magazine or book while using transportation once in a while, and contribute to a higher quality of life for yourself and your community. Don't let the perfect [a completely car-free society] get in the way of the good [a society where the average miles driven per driver is under 5,000, or even less].

Re:Measuring changes results

[SvetBeard]

I work in the traffic engineering industry. There are two things you have to realize about speeding: first, many speed limits are set artificially low and second, speed itself isn't dangerous--it's the difference in speed that causes accidents.

The accepted method for setting speed limits is to collect speed data on all vehicles on the road for 24 hours on a typical day. This is usually done using those two rubber tubes you may see placed across the road at times. The speed limit is then supposed to be set at the 85th percentile speed of the traffic. In reality, political considerations often force the speed limit to be something ridiculous like 55 mph. If 85 percent of the traffic is doing 70 mph, that speed limit is unrealistic and will be ignored.

The other part of this is the common misconception that slowing the traffic down will make everything safer. While it is true that accidents that happen at higher speeds are more severe, accidents are caused by difference is speeds. Studies have shown that the number of accidents sharply increases when the differences in speeds between vehicles exceed 20 mph. This means that if you are the guy driving 55 mph when everyone else is doing 80, you are the one driving recklessly. Because of this fact, artificially low speed limits can actually cause accidents.

This standard from the Institute of Transportation Engineers sums everything up nicely: http://www.ite.org/standards/speed_zoning.pdf [ite.org]