# Road Question... **URL:** \ **Category:** NYSpeed Off Topic\ **Created:** [October 31, 2007, 8:34pm UTC](https://forums.speedlife.net/t/road-question/37960 "2007-10-31T20:34:08Z")\ **Posts on this page:** 11\ **Page:** 2
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [November 1, 2007, 6:51am UTC](https://forums.speedlife.net/t/road-question/37960/21 "2007-11-01T06:51:01Z")
Also, being a foot apart, a vehicle traveling at 60mph will have a delta T of .0113 with a variation of .0008 per MPH… which is hardly outside the realm of a pressure sensor operating at 20K hertz. ---
**Author:** ![JayS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jays/32/15375_2.png) [@JayS](https://forums.speedlife.net/u/JayS)\ **Post date:** [November 1, 2007, 6:52am UTC](https://forums.speedlife.net/t/road-question/37960/22 "2007-11-01T06:52:00Z")
[quote=“Fry,post:18,topic:37960"”] lol “wires across road” [/quote] That’s what I first put in, which got me to a yahoo answers page which had the real name for them. I googled that and got the roadrampsystems site. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [November 1, 2007, 7:10am UTC](https://forums.speedlife.net/t/road-question/37960/23 "2007-11-01T07:10:53Z")
[quote=“newman,post:21,topic:37960"”] Also, being a foot apart, a vehicle traveling at 60mph will have a delta T of .0113 with a variation of .0008 per MPH… which is hardly outside the realm of a pressure sensor operating at 20K hertz. [/quote] I wonder how accurate they are. To be accurate within 5mph (~8%) you would need the timer to be precise down to about .0009 second, assuming that the rest of the system (input from the pressure switches) is dead nuts on. ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [November 1, 2007, 7:14am UTC](https://forums.speedlife.net/t/road-question/37960/24 "2007-11-01T07:14:44Z")
[quote=“Fry,post:23,topic:37960"”] I wonder how accurate they are. To be accurate within 5mph (~8%) you would need the timer to be precise down to about .0009 second, assuming that the rest of the system (input from the pressure switches) is dead nuts on. [/quote] yeah, my original post i meant .0008 per 5mph. a lot of the latency in the system can be negated because it’s consistent between the two. the pressure transducer is just a piezo, and should be fairly simple to calibrate. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [November 1, 2007, 7:35am UTC](https://forums.speedlife.net/t/road-question/37960/25 "2007-11-01T07:35:54Z")
Oh I was wondering what you meant by variance. ---
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [November 1, 2007, 8:05am UTC](https://forums.speedlife.net/t/road-question/37960/26 "2007-11-01T08:05:03Z")
How would it take into account that the line crosses two lanes though? What if two cars are driving in relative closeness in consecutive lanes? How can you determine the difference between a semi and two cars tailgating? Semi’s don’t always have dual axles front and rear, and trailer length varies. Unless the data is processed by a relatively advanced computer program to filter out only usable data I don’t see how successful one crossing two lanes would be. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [November 1, 2007, 8:32am UTC](https://forums.speedlife.net/t/road-question/37960/27 "2007-11-01T08:32:06Z")
A-\>B = North B-\>A = South There is probably some logic that counts all inputs at exactly the same speed within 2 seconds as one vehicle or something. ---
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [November 1, 2007, 9:19am UTC](https://forums.speedlife.net/t/road-question/37960/28 "2007-11-01T09:19:27Z")
Yes there would need to be some sort of logic filter. I meant two lanes of same direction, as in one side of a 4 lain road. It seems though that there would be some error as I can’t see a logic accounting for every situation correctly. ---
**Author:** ![MazerMadness](https://avatars.discourse-cdn.com/v4/letter/m/90db22/32.png) [@MazerMadness](https://forums.speedlife.net/u/MazerMadness)\ **Post date:** [November 1, 2007, 9:37am UTC](https://forums.speedlife.net/t/road-question/37960/29 "2007-11-01T09:37:07Z")
well I looked it up and it is a traffic counter, now you can post irrelevant replies elsewhere. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [November 1, 2007, 9:42am UTC](https://forums.speedlife.net/t/road-question/37960/30 "2007-11-01T09:42:25Z")
The fuck? Did you not read anything beyond the first post? This entire thread has been on topic, and at post 14 I told you to what it was and linked you to a manufacturer’s website. ---
**Author:** ![Haenszel](https://avatars.discourse-cdn.com/v4/letter/h/e68b1a/32.png) [@Haenszel](https://forums.speedlife.net/u/Haenszel)\ **Post date:** [November 1, 2007, 9:49am UTC](https://forums.speedlife.net/t/road-question/37960/31 "2007-11-01T09:49:42Z")
[quote=“MazerMadness,post:29,topic:37960"”] well I looked it up and it is a traffic counter, now you can post irrelevant replies elsewhere. [/quote] :sario:Good job. [Previous page](https://forums.speedlife.net/t/road-question/37960.md?page=1)