Re:Why's that company so big? I could do that in a weekend
by stan_rogers on Monday October 03, 2016 @11:35PM
(#12633153)
When I said "worked", I meant worked, not approximated working or came lose enough not to have caused too many upsets. If expectations have grown to be higher than plus-ten-second accuracy (early wasn't tolerated), then we collectively need some sort of counselling/therapy.
Re:Why's that company so big? I could do that in a weekend
by vidarh on Tuesday October 04, 2016 @10:17AM
(#12635674)
You don't get that kind of accuracy in any system that has to deal with congested roads, or any dense major city. E.g. there's plenty of bus-stops near me where stops on the same route involves going around corners and traffic machines and stopping close enough that GPS would be insufficient to be guaranteed to tell the stops apart if you don't get a good enough fix on additional satellites quickly enough.
Even with all the extra data, and a lot number crunching, in London it's a challenge to get it to withing a few minutes during rush hour.
So, sure, if you're dealing with simple, small systems with little congestion, you can simplify.
Consider that e.g. in London the old route indicators on the buses used odometers. Which worked for telling you were along the route a bus was. Most of the time. But didn't tell you how long it takes until the bus reaches the next stop other than on average, as it would tell you nothing about traffic etc.
Today London buses don't use just GPS to replace it either, because that's nowhere near good enough. See the "Tracking" section here [1].
https://en.wikipedia.org/wiki/IBus_(London)